Commit Graph

683 Commits

Author SHA1 Message Date
Kuniyuki Iwashima
b5c0898807 af_unix: Remove dead code in unix_stream_read_generic().
When splice() support was added in commit 2b514574f7 ("net:
af_unix: implement splice for stream af_unix sockets"), we had
to release unix_sk(sk)->readlock (current iolock) before calling
splice_to_pipe().

Due to the unlock, commit 73ed5d25dc ("af-unix: fix use-after-free
with concurrent readers while splicing") added a safeguard in
unix_stream_read_generic(); we had to bump the skb refcount before
calling ->recv_actor() and then check if the skb was consumed by a
concurrent reader.

However, the pipe side locking was refactored, and since commit
25869262ef ("skb_splice_bits(): get rid of callback"), we can
call splice_to_pipe() without releasing unix_sk(sk)->iolock.

Now, the skb is always alive after the ->recv_actor() callback,
so let's remove the unnecessary drop_skb logic.

This is mostly the revert of commit 73ed5d25dc ("af-unix: fix
use-after-free with concurrent readers while splicing").

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240529144648.68591-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-01 16:28:55 -07:00
Kuniyuki Iwashima
51d1b25a72 af_unix: Read sk->sk_hash under bindlock during bind().
syzkaller reported data-race of sk->sk_hash in unix_autobind() [0],
and the same ones exist in unix_bind_bsd() and unix_bind_abstract().

The three bind() functions prefetch sk->sk_hash locklessly and
use it later after validating that unix_sk(sk)->addr is NULL under
unix_sk(sk)->bindlock.

The prefetched sk->sk_hash is the hash value of unbound socket set
in unix_create1() and does not change until bind() completes.

There could be a chance that sk->sk_hash changes after the lockless
read.  However, in such a case, non-NULL unix_sk(sk)->addr is visible
under unix_sk(sk)->bindlock, and bind() returns -EINVAL without using
the prefetched value.

The KCSAN splat is false-positive, but let's silence it by reading
sk->sk_hash under unix_sk(sk)->bindlock.

[0]:
BUG: KCSAN: data-race in unix_autobind / unix_autobind

write to 0xffff888034a9fb88 of 4 bytes by task 4468 on cpu 0:
 __unix_set_addr_hash net/unix/af_unix.c:331 [inline]
 unix_autobind+0x47a/0x7d0 net/unix/af_unix.c:1185
 unix_dgram_connect+0x7e3/0x890 net/unix/af_unix.c:1373
 __sys_connect_file+0xd7/0xe0 net/socket.c:2048
 __sys_connect+0x114/0x140 net/socket.c:2065
 __do_sys_connect net/socket.c:2075 [inline]
 __se_sys_connect net/socket.c:2072 [inline]
 __x64_sys_connect+0x40/0x50 net/socket.c:2072
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e

read to 0xffff888034a9fb88 of 4 bytes by task 4465 on cpu 1:
 unix_autobind+0x28/0x7d0 net/unix/af_unix.c:1134
 unix_dgram_connect+0x7e3/0x890 net/unix/af_unix.c:1373
 __sys_connect_file+0xd7/0xe0 net/socket.c:2048
 __sys_connect+0x114/0x140 net/socket.c:2065
 __do_sys_connect net/socket.c:2075 [inline]
 __se_sys_connect net/socket.c:2072 [inline]
 __x64_sys_connect+0x40/0x50 net/socket.c:2072
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e

value changed: 0x000000e4 -> 0x000001e3

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4465 Comm: syz-executor.0 Not tainted 6.8.0-12822-gcd51db110a7e #12
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: afd20b9290 ("af_unix: Replace the big lock with small locks.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240522154218.78088-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-27 11:46:56 +02:00
Kuniyuki Iwashima
97e1db06c7 af_unix: Annotate data-race around unix_sk(sk)->addr.
Once unix_sk(sk)->addr is assigned under net->unx.table.locks and
unix_sk(sk)->bindlock, *(unix_sk(sk)->addr) and unix_sk(sk)->path are
fully set up, and unix_sk(sk)->addr is never changed.

unix_getname() and unix_copy_addr() access the two fields locklessly,
and commit ae3b564179 ("missing barriers in some of unix_sock ->addr
and ->path accesses") added smp_store_release() and smp_load_acquire()
pairs.

In other functions, we still read unix_sk(sk)->addr locklessly to check
if the socket is bound, and KCSAN complains about it.  [0]

Given these functions have no dependency for *(unix_sk(sk)->addr) and
unix_sk(sk)->path, READ_ONCE() is enough to annotate the data-race.

Note that it is safe to access unix_sk(sk)->addr locklessly if the socket
is found in the hash table.  For example, the lockless read of otheru->addr
in unix_stream_connect() is safe.

Note also that newu->addr there is of the child socket that is still not
accessible from userspace, and smp_store_release() publishes the address
in case the socket is accept()ed and unix_getname() / unix_copy_addr()
is called.

[0]:
BUG: KCSAN: data-race in unix_bind / unix_listen

write (marked) to 0xffff88805f8d1840 of 8 bytes by task 13723 on cpu 0:
 __unix_set_addr_hash net/unix/af_unix.c:329 [inline]
 unix_bind_bsd net/unix/af_unix.c:1241 [inline]
 unix_bind+0x881/0x1000 net/unix/af_unix.c:1319
 __sys_bind+0x194/0x1e0 net/socket.c:1847
 __do_sys_bind net/socket.c:1858 [inline]
 __se_sys_bind net/socket.c:1856 [inline]
 __x64_sys_bind+0x40/0x50 net/socket.c:1856
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e

read to 0xffff88805f8d1840 of 8 bytes by task 13724 on cpu 1:
 unix_listen+0x72/0x180 net/unix/af_unix.c:734
 __sys_listen+0xdc/0x160 net/socket.c:1881
 __do_sys_listen net/socket.c:1890 [inline]
 __se_sys_listen net/socket.c:1888 [inline]
 __x64_sys_listen+0x2e/0x40 net/socket.c:1888
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e

value changed: 0x0000000000000000 -> 0xffff88807b5b1b40

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13724 Comm: syz-executor.4 Not tainted 6.8.0-12822-gcd51db110a7e #12
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240522154002.77857-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-27 11:46:31 +02:00
Linus Torvalds
66ad4829dd Quite smaller than usual. Notably it includes the fix for the unix
regression you have been notified of in the past weeks.
 The TCP window fix will require some follow-up, already queued.
 
 Current release - regressions:
 
   - af_unix: fix garbage collection of embryos
 
 Previous releases - regressions:
 
   - af_unix: fix race between GC and receive path
 
   - ipv6: sr: fix missing sk_buff release in seg6_input_core
 
   - tcp: remove 64 KByte limit for initial tp->rcv_wnd value
 
   - eth: r8169: fix rx hangup
 
   - eth: lan966x: remove ptp traps in case the ptp is not enabled.
 
   - eth: ixgbe: fix link breakage vs cisco switches.
 
   - eth: ice: prevent ethtool from corrupting the channels.
 
 Previous releases - always broken:
 
   - openvswitch: set the skbuff pkt_type for proper pmtud support.
 
   - tcp: Fix shift-out-of-bounds in dctcp_update_alpha().
 
 Misc:
 
   - a bunch of selftests stabilization patches.
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Quite smaller than usual. Notably it includes the fix for the unix
  regression from the past weeks. The TCP window fix will require some
  follow-up, already queued.

  Current release - regressions:

   - af_unix: fix garbage collection of embryos

  Previous releases - regressions:

   - af_unix: fix race between GC and receive path

   - ipv6: sr: fix missing sk_buff release in seg6_input_core

   - tcp: remove 64 KByte limit for initial tp->rcv_wnd value

   - eth: r8169: fix rx hangup

   - eth: lan966x: remove ptp traps in case the ptp is not enabled

   - eth: ixgbe: fix link breakage vs cisco switches

   - eth: ice: prevent ethtool from corrupting the channels

  Previous releases - always broken:

   - openvswitch: set the skbuff pkt_type for proper pmtud support

   - tcp: Fix shift-out-of-bounds in dctcp_update_alpha()

  Misc:

   - a bunch of selftests stabilization patches"

* tag 'net-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (25 commits)
  r8169: Fix possible ring buffer corruption on fragmented Tx packets.
  idpf: Interpret .set_channels() input differently
  ice: Interpret .set_channels() input differently
  nfc: nci: Fix handling of zero-length payload packets in nci_rx_work()
  net: relax socket state check at accept time.
  tcp: remove 64 KByte limit for initial tp->rcv_wnd value
  net: ti: icssg_prueth: Fix NULL pointer dereference in prueth_probe()
  tls: fix missing memory barrier in tls_init
  net: fec: avoid lock evasion when reading pps_enable
  Revert "ixgbe: Manual AN-37 for troublesome link partners for X550 SFI"
  testing: net-drv: use stats64 for testing
  net: mana: Fix the extra HZ in mana_hwc_send_request
  net: lan966x: Remove ptp traps in case the ptp is not enabled.
  openvswitch: Set the skbuff pkt_type for proper pmtud support.
  selftest: af_unix: Make SCM_RIGHTS into OOB data.
  af_unix: Fix garbage collection of embryos carrying OOB with SCM_RIGHTS
  tcp: Fix shift-out-of-bounds in dctcp_update_alpha().
  selftests/net: use tc rule to filter the na packet
  ipv6: sr: fix memleak in seg6_hmac_init_algo
  af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock.
  ...
2024-05-23 12:49:37 -07:00
Michal Luczaj
041933a1ec af_unix: Fix garbage collection of embryos carrying OOB with SCM_RIGHTS
GC attempts to explicitly drop oob_skb's reference before purging the hit
list.

The problem is with embryos: kfree_skb(u->oob_skb) is never called on an
embryo socket.

The python script below [0] sends a listener's fd to its embryo as OOB
data.  While GC does collect the embryo's queue, it fails to drop the OOB
skb's refcount.  The skb which was in embryo's receive queue stays as
unix_sk(sk)->oob_skb and keeps the listener's refcount [1].

Tell GC to dispose embryo's oob_skb.

[0]:
from array import array
from socket import *

addr = '\x00unix-oob'
lis = socket(AF_UNIX, SOCK_STREAM)
lis.bind(addr)
lis.listen(1)

s = socket(AF_UNIX, SOCK_STREAM)
s.connect(addr)
scm = (SOL_SOCKET, SCM_RIGHTS, array('i', [lis.fileno()]))
s.sendmsg([b'x'], [scm], MSG_OOB)
lis.close()

[1]
$ grep unix-oob /proc/net/unix
$ ./unix-oob.py
$ grep unix-oob /proc/net/unix
0000000000000000: 00000002 00000000 00000000 0001 02     0 @unix-oob
0000000000000000: 00000002 00000000 00010000 0001 01  6072 @unix-oob

Fixes: 4090fa373f ("af_unix: Replace garbage collection algorithm.")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-21 13:42:02 +02:00
Kuniyuki Iwashima
9841991a44 af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock.
Billy Jheng Bing-Jhong reported a race between __unix_gc() and
queue_oob().

__unix_gc() tries to garbage-collect close()d inflight sockets,
and then if the socket has MSG_OOB in unix_sk(sk)->oob_skb, GC
will drop the reference and set NULL to it locklessly.

However, the peer socket still can send MSG_OOB message and
queue_oob() can update unix_sk(sk)->oob_skb concurrently, leading
NULL pointer dereference. [0]

To fix the issue, let's update unix_sk(sk)->oob_skb under the
sk_receive_queue's lock and take it everywhere we touch oob_skb.

Note that we defer kfree_skb() in manage_oob() to silence lockdep
false-positive (See [1]).

[0]:
BUG: kernel NULL pointer dereference, address: 0000000000000008
 PF: supervisor write access in kernel mode
 PF: error_code(0x0002) - not-present page
PGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0
Oops: 0002 [#1] PREEMPT SMP PTI
CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc5-00191-gd091e579b864 #110
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: events delayed_fput
RIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff.c:3847)
Code: 39 e3 74 3e 8b 43 10 48 89 ef 83 e8 01 89 43 10 49 8b 44 24 08 49 c7 44 24 08 00 00 00 00 49 8b 14 24 49 c7 04 24 00 00 00 00 <48> 89 42 08 48 89 10 e8 e7 c5 42 00 4c 89 e0 5b 5d 41 5c c3 cc cc
RSP: 0018:ffffc900001bfd48 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff8880088f5ae8 RCX: 00000000361289f9
RDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00
RBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001
R10: 0000000000000003 R11: 0000000000000001 R12: ffff8880056b6a00
R13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80
FS:  0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
 <TASK>
 unix_release_sock (net/unix/af_unix.c:654)
 unix_release (net/unix/af_unix.c:1050)
 __sock_release (net/socket.c:660)
 sock_close (net/socket.c:1423)
 __fput (fs/file_table.c:423)
 delayed_fput (fs/file_table.c:444 (discriminator 3))
 process_one_work (kernel/workqueue.c:3259)
 worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416)
 kthread (kernel/kthread.c:388)
 ret_from_fork (arch/x86/kernel/process.c:153)
 ret_from_fork_asm (arch/x86/entry/entry_64.S:257)
 </TASK>
Modules linked in:
CR2: 0000000000000008

Link: https://lore.kernel.org/netdev/a00d3993-c461-43f2-be6d-07259c98509a@rbox.co/ [1]
Fixes: 1279f9d9de ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.")
Reported-by: Billy Jheng Bing-Jhong <billy@starlabs.sg>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240516134835.8332-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-21 12:04:45 +02:00
Linus Torvalds
89721e3038 net-accept-more-20240515
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Merge tag 'net-accept-more-20240515' of git://git.kernel.dk/linux

Pull more io_uring updates from Jens Axboe:
 "This adds support for IORING_CQE_F_SOCK_NONEMPTY for io_uring accept
  requests.

  This is very similar to previous work that enabled the same hint for
  doing receives on sockets. By far the majority of the work here is
  refactoring to enable the networking side to pass back whether or not
  the socket had more pending requests after accepting the current one,
  the last patch just wires it up for io_uring.

  Not only does this enable applications to know whether there are more
  connections to accept right now, it also enables smarter logic for
  io_uring multishot accept on whether to retry immediately or wait for
  a poll trigger"

* tag 'net-accept-more-20240515' of git://git.kernel.dk/linux:
  io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept
  net: pass back whether socket was empty post accept
  net: have do_accept() take a struct proto_accept_arg argument
  net: change proto and proto_ops accept type
2024-05-18 10:32:39 -07:00
Jakub Kicinski
654de42f3f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes to prepare for the 6.10 net-next PR.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-14 10:53:19 -07:00
Jens Axboe
92ef0fd55a net: change proto and proto_ops accept type
Rather than pass in flags, error pointer, and whether this is a kernel
invocation or not, add a struct proto_accept_arg struct as the argument.
This then holds all of these arguments, and prepares accept for being
able to pass back more information.

No functional changes in this patch.

Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-13 18:19:09 -06:00
Breno Leitao
540bf24fba af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg
A data-race condition has been identified in af_unix. In one data path,
the write function unix_release_sock() atomically writes to
sk->sk_shutdown using WRITE_ONCE. However, on the reader side,
unix_stream_sendmsg() does not read it atomically. Consequently, this
issue is causing the following KCSAN splat to occur:

	BUG: KCSAN: data-race in unix_release_sock / unix_stream_sendmsg

	write (marked) to 0xffff88867256ddbb of 1 bytes by task 7270 on cpu 28:
	unix_release_sock (net/unix/af_unix.c:640)
	unix_release (net/unix/af_unix.c:1050)
	sock_close (net/socket.c:659 net/socket.c:1421)
	__fput (fs/file_table.c:422)
	__fput_sync (fs/file_table.c:508)
	__se_sys_close (fs/open.c:1559 fs/open.c:1541)
	__x64_sys_close (fs/open.c:1541)
	x64_sys_call (arch/x86/entry/syscall_64.c:33)
	do_syscall_64 (arch/x86/entry/common.c:?)
	entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

	read to 0xffff88867256ddbb of 1 bytes by task 989 on cpu 14:
	unix_stream_sendmsg (net/unix/af_unix.c:2273)
	__sock_sendmsg (net/socket.c:730 net/socket.c:745)
	____sys_sendmsg (net/socket.c:2584)
	__sys_sendmmsg (net/socket.c:2638 net/socket.c:2724)
	__x64_sys_sendmmsg (net/socket.c:2753 net/socket.c:2750 net/socket.c:2750)
	x64_sys_call (arch/x86/entry/syscall_64.c:33)
	do_syscall_64 (arch/x86/entry/common.c:?)
	entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

	value changed: 0x01 -> 0x03

The line numbers are related to commit dd5a440a31 ("Linux 6.9-rc7").

Commit e1d09c2c2f ("af_unix: Fix data races around sk->sk_shutdown.")
addressed a comparable issue in the past regarding sk->sk_shutdown.
However, it overlooked resolving this particular data path.
This patch only offending unix_stream_sendmsg() function, since the
other reads seem to be protected by unix_state_lock() as discussed in
Link: https://lore.kernel.org/all/20240508173324.53565-1-kuniyu@amazon.com/

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240509081459.2807828-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-10 19:22:26 -07:00
Kuniyuki Iwashima
7172dc93d6 af_unix: Add dead flag to struct scm_fp_list.
Commit 1af2dface5 ("af_unix: Don't access successor in unix_del_edges()
during GC.") fixed use-after-free by avoid accessing edge->successor while
GC is in progress.

However, there could be a small race window where another process could
call unix_del_edges() while gc_in_progress is true and __skb_queue_purge()
is on the way.

So, we need another marker for struct scm_fp_list which indicates if the
skb is garbage-collected.

This patch adds dead flag in struct scm_fp_list and set it true before
calling __skb_queue_purge().

Fixes: 1af2dface5 ("af_unix: Don't access successor in unix_del_edges() during GC.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240508171150.50601-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-10 18:52:45 -07:00
Joel Granados
ce218712b0 net: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

* Remove sentinel element from ctl_table structs.
* Remove the zeroing out of an array element (to make it look like a
  sentinel) in neigh_sysctl_register and lowpan_frags_ns_sysctl_register
  This is not longer needed and is safe after commit c899710fe7
  ("networking: Update to register_net_sysctl_sz") added the array size
  to the ctl_table registration.
* Replace the for loop stop condition in sysctl_core_net_init that tests
  for procname == NULL with one that depends on array size
* Removed the "-1" in mpls_net_init that adjusted for having an extra
  empty element when looping over ctl_table arrays
* Use a table_size variable to keep the value of ARRAY_SIZE

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-05-03 13:29:41 +01:00
Kuniyuki Iwashima
1971d13ffa af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc().
syzbot reported a lockdep splat regarding unix_gc_lock and
unix_state_lock().

One is called from recvmsg() for a connected socket, and another
is called from GC for TCP_LISTEN socket.

So, the splat is false-positive.

Let's add a dedicated lock class for the latter to suppress the splat.

Note that this change is not necessary for net-next.git as the issue
is only applied to the old GC impl.

[0]:
WARNING: possible circular locking dependency detected
6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0 Not tainted
 -----------------------------------------------------
kworker/u8:1/11 is trying to acquire lock:
ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: __unix_gc+0x40e/0xf70 net/unix/garbage.c:302

but task is already holding lock:
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> #1 (unix_gc_lock){+.+.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       unix_notinflight+0x13d/0x390 net/unix/garbage.c:140
       unix_detach_fds net/unix/af_unix.c:1819 [inline]
       unix_destruct_scm+0x221/0x350 net/unix/af_unix.c:1876
       skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188
       skb_release_all net/core/skbuff.c:1200 [inline]
       __kfree_skb net/core/skbuff.c:1216 [inline]
       kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1252
       kfree_skb include/linux/skbuff.h:1262 [inline]
       manage_oob net/unix/af_unix.c:2672 [inline]
       unix_stream_read_generic+0x1125/0x2700 net/unix/af_unix.c:2749
       unix_stream_splice_read+0x239/0x320 net/unix/af_unix.c:2981
       do_splice_read fs/splice.c:985 [inline]
       splice_file_to_pipe+0x299/0x500 fs/splice.c:1295
       do_splice+0xf2d/0x1880 fs/splice.c:1379
       __do_splice fs/splice.c:1436 [inline]
       __do_sys_splice fs/splice.c:1652 [inline]
       __se_sys_splice+0x331/0x4a0 fs/splice.c:1634
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #0 (&u->lock){+.+.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
       process_one_work kernel/workqueue.c:3254 [inline]
       process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
       worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
       kthread+0x2f0/0x390 kernel/kthread.c:388
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(unix_gc_lock);
                               lock(&u->lock);
                               lock(unix_gc_lock);
  lock(&u->lock);

 *** DEADLOCK ***

3 locks held by kworker/u8:1/11:
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335
 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335
 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261

stack backtrace:
CPU: 0 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Fixes: 47d8ac011f ("af_unix: Fix garbage collector racing against connect()")
Reported-and-tested-by: syzbot+fa379358c28cc87cc307@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fa379358c28cc87cc307
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240424170443.9832-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-25 08:37:02 -07:00
Kuniyuki Iwashima
1af2dface5 af_unix: Don't access successor in unix_del_edges() during GC.
syzbot reported use-after-free in unix_del_edges().  [0]

What the repro does is basically repeat the following quickly.

  1. pass a fd of an AF_UNIX socket to itself

    socketpair(AF_UNIX, SOCK_DGRAM, 0, [3, 4]) = 0
    sendmsg(3, {..., msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET,
                                   cmsg_type=SCM_RIGHTS, cmsg_data=[4]}], ...}, 0) = 0

  2. pass other fds of AF_UNIX sockets to the socket above

    socketpair(AF_UNIX, SOCK_SEQPACKET, 0, [5, 6]) = 0
    sendmsg(3, {..., msg_control=[{cmsg_len=48, cmsg_level=SOL_SOCKET,
                                   cmsg_type=SCM_RIGHTS, cmsg_data=[5, 6]}], ...}, 0) = 0

  3. close all sockets

Here, two skb are created, and every unix_edge->successor is the first
socket.  Then, __unix_gc() will garbage-collect the two skb:

  (a) free skb with self-referencing fd
  (b) free skb holding other sockets

After (a), the self-referencing socket will be scheduled to be freed
later by the delayed_fput() task.

syzbot repeated the sequences above (1. ~ 3.) quickly and triggered
the task concurrently while GC was running.

So, at (b), the socket was already freed, and accessing it was illegal.

unix_del_edges() accesses the receiver socket as edge->successor to
optimise GC.  However, we should not do it during GC.

Garbage-collecting sockets does not change the shape of the rest
of the graph, so we need not call unix_update_graph() to update
unix_graph_grouped when we purge skb.

However, if we clean up all loops in the unix_walk_scc_fast() path,
unix_graph_maybe_cyclic remains unchanged (true), and __unix_gc()
will call unix_walk_scc_fast() continuously even though there is no
socket to garbage-collect.

To keep that optimisation while fixing UAF, let's add the same
updating logic of unix_graph_maybe_cyclic in unix_walk_scc_fast()
as done in unix_walk_scc() and __unix_walk_scc().

Note that when unix_del_edges() is called from other places, the
receiver socket is always alive:

  - sendmsg: the successor's sk_refcnt is bumped by sock_hold()
             unix_find_other() for SOCK_DGRAM, connect() for SOCK_STREAM

  - recvmsg: the successor is the receiver, and its fd is alive

[0]:
BUG: KASAN: slab-use-after-free in unix_edge_successor net/unix/garbage.c:109 [inline]
BUG: KASAN: slab-use-after-free in unix_del_edge net/unix/garbage.c:165 [inline]
BUG: KASAN: slab-use-after-free in unix_del_edges+0x148/0x630 net/unix/garbage.c:237
Read of size 8 at addr ffff888079c6e640 by task kworker/u8:6/1099

CPU: 0 PID: 1099 Comm: kworker/u8:6 Not tainted 6.9.0-rc4-next-20240418-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 unix_edge_successor net/unix/garbage.c:109 [inline]
 unix_del_edge net/unix/garbage.c:165 [inline]
 unix_del_edges+0x148/0x630 net/unix/garbage.c:237
 unix_destroy_fpl+0x59/0x210 net/unix/garbage.c:298
 unix_detach_fds net/unix/af_unix.c:1811 [inline]
 unix_destruct_scm+0x13e/0x210 net/unix/af_unix.c:1826
 skb_release_head_state+0x100/0x250 net/core/skbuff.c:1127
 skb_release_all net/core/skbuff.c:1138 [inline]
 __kfree_skb net/core/skbuff.c:1154 [inline]
 kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1190
 __skb_queue_purge_reason include/linux/skbuff.h:3251 [inline]
 __skb_queue_purge include/linux/skbuff.h:3256 [inline]
 __unix_gc+0x1732/0x1830 net/unix/garbage.c:575
 process_one_work kernel/workqueue.c:3218 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 14427:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3897 [inline]
 slab_alloc_node mm/slub.c:3957 [inline]
 kmem_cache_alloc_noprof+0x135/0x290 mm/slub.c:3964
 sk_prot_alloc+0x58/0x210 net/core/sock.c:2074
 sk_alloc+0x38/0x370 net/core/sock.c:2133
 unix_create1+0xb4/0x770
 unix_create+0x14e/0x200 net/unix/af_unix.c:1034
 __sock_create+0x490/0x920 net/socket.c:1571
 sock_create net/socket.c:1622 [inline]
 __sys_socketpair+0x33e/0x720 net/socket.c:1773
 __do_sys_socketpair net/socket.c:1822 [inline]
 __se_sys_socketpair net/socket.c:1819 [inline]
 __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1805:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2190 [inline]
 slab_free mm/slub.c:4393 [inline]
 kmem_cache_free+0x145/0x340 mm/slub.c:4468
 sk_prot_free net/core/sock.c:2114 [inline]
 __sk_destruct+0x467/0x5f0 net/core/sock.c:2208
 sock_put include/net/sock.h:1948 [inline]
 unix_release_sock+0xa8b/0xd20 net/unix/af_unix.c:665
 unix_release+0x91/0xc0 net/unix/af_unix.c:1049
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 delayed_fput+0x59/0x80 fs/file_table.c:445
 process_one_work kernel/workqueue.c:3218 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff888079c6e000
 which belongs to the cache UNIX of size 1920
The buggy address is located 1600 bytes inside of
 freed 1920-byte region [ffff888079c6e000, ffff888079c6e780)

Reported-by: syzbot+f3f3eef1d2100200e593@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f3f3eef1d2100200e593
Fixes: 77e5593aeb ("af_unix: Skip GC if no cycle exists.")
Fixes: fd86344823 ("af_unix: Try not to hold unix_gc_lock during accept().")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240419235102.31707-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-23 13:57:35 +02:00
Thomas Weißschuh
bfa858f220 sysctl: treewide: constify ctl_table_header::ctl_table_arg
To be able to constify instances of struct ctl_tables it is necessary to
remove ways through which non-const versions are exposed from the
sysctl core.
One of these is the ctl_table_arg member of struct ctl_table_header.

Constify this reference as a prerequisite for the full constification of
struct ctl_table instances.
No functional change.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-22 08:56:31 +01:00
Jakub Kicinski
41e3ddb291 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/trace/events/rpcgss.h
  386f4a7379 ("trace: events: cleanup deprecated strncpy uses")
  a4833e3aba ("SUNRPC: Fix rpcgss_context trace event acceptor field")

Adjacent changes:

drivers/net/ethernet/intel/ice/ice_tc_lib.c
  2cca35f5dd ("ice: Fix checking for unsupported keys on non-tunnel device")
  784feaa65d ("ice: Add support for PFCP hardware offload in switchdev")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-18 13:12:24 -07:00
Kuniyuki Iwashima
fd86344823 af_unix: Try not to hold unix_gc_lock during accept().
Commit dcf70df204 ("af_unix: Fix up unix_edge.successor for embryo
socket.") added spin_lock(&unix_gc_lock) in accept() path, and it
caused regression in a stress test as reported by kernel test robot.

If the embryo socket is not part of the inflight graph, we need not
hold the lock.

To decide that in O(1) time and avoid the regression in the normal
use case,

  1. add a new stat unix_sk(sk)->scm_stat.nr_unix_fds

  2. count the number of inflight AF_UNIX sockets in the receive
     queue under unix_state_lock()

  3. move unix_update_edges() call under unix_state_lock()

  4. avoid locking if nr_unix_fds is 0 in unix_update_edges()

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202404101427.92a08551-oliver.sang@intel.com
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240413021928.20946-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-16 13:50:57 +02:00
Kuniyuki Iwashima
22dd70eb2c af_unix: Don't peek OOB data without MSG_OOB.
Currently, we can read OOB data without MSG_OOB by using MSG_PEEK
when OOB data is sitting on the front row, which is apparently
wrong.

  >>> from socket import *
  >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
  >>> c1.send(b'a', MSG_OOB)
  1
  >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT)
  b'a'

If manage_oob() is called when no data has been copied, we only
check if the socket enables SO_OOBINLINE or MSG_PEEK is not used.
Otherwise, the skb is returned as is.

However, here we should return NULL if MSG_PEEK is set and no data
has been copied.

Also, in such a case, we should not jump to the redo label because
we will be caught in the loop and hog the CPU until normal data
comes in.

Then, we need to handle skb == NULL case with the if-clause below
the manage_oob() block.

With this patch:

  >>> from socket import *
  >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
  >>> c1.send(b'a', MSG_OOB)
  1
  >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT)
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  BlockingIOError: [Errno 11] Resource temporarily unavailable

Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240410171016.7621-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-12 19:05:49 -07:00
Kuniyuki Iwashima
283454c8a1 af_unix: Call manage_oob() for every skb in unix_stream_read_generic().
When we call recv() for AF_UNIX socket, we first peek one skb and
calls manage_oob() to check if the skb is sent with MSG_OOB.

However, when we fetch the next (and the following) skb, manage_oob()
is not called now, leading a wrong behaviour.

Let's say a socket send()s "hello" with MSG_OOB and the peer tries
to recv() 5 bytes with MSG_PEEK.  Here, we should get only "hell"
without 'o', but actually not:

  >>> from socket import *
  >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
  >>> c1.send(b'hello', MSG_OOB)
  5
  >>> c2.recv(5, MSG_PEEK)
  b'hello'

The first skb fills 4 bytes, and the next skb is peeked but not
properly checked by manage_oob().

Let's move up the again label to call manage_oob() for evry skb.

With this patch:

  >>> from socket import *
  >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
  >>> c1.send(b'hello', MSG_OOB)
  5
  >>> c2.recv(5, MSG_PEEK)
  b'hell'

Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240410171016.7621-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-12 19:05:48 -07:00
Jakub Kicinski
94426ed213 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/unix/garbage.c
  47d8ac011f ("af_unix: Fix garbage collector racing against connect()")
  4090fa373f ("af_unix: Replace garbage collection algorithm.")

Adjacent changes:

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  faa12ca245 ("bnxt_en: Reset PTP tx_avail after possible firmware reset")
  b3d0083caf ("bnxt_en: Support RSS contexts in ethtool .{get|set}_rxfh()")

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
  7ac10c7d72 ("bnxt_en: Fix possible memory leak in bnxt_rdma_aux_device_init()")
  194fad5b27 ("bnxt_en: Refactor bnxt_rdma_aux_device_init/uninit functions")

drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
  958f56e483 ("net/mlx5e: Un-expose functions in en.h")
  49e6c93870 ("net/mlx5e: RSS, Block XOR hash with over 128 channels")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-11 14:23:47 -07:00
Michal Luczaj
47d8ac011f af_unix: Fix garbage collector racing against connect()
Garbage collector does not take into account the risk of embryo getting
enqueued during the garbage collection. If such embryo has a peer that
carries SCM_RIGHTS, two consecutive passes of scan_children() may see a
different set of children. Leading to an incorrectly elevated inflight
count, and then a dangling pointer within the gc_inflight_list.

sockets are AF_UNIX/SOCK_STREAM
S is an unconnected socket
L is a listening in-flight socket bound to addr, not in fdtable
V's fd will be passed via sendmsg(), gets inflight count bumped

connect(S, addr)	sendmsg(S, [V]); close(V)	__unix_gc()
----------------	-------------------------	-----------

NS = unix_create1()
skb1 = sock_wmalloc(NS)
L = unix_find_other(addr)
unix_state_lock(L)
unix_peer(S) = NS
			// V count=1 inflight=0

 			NS = unix_peer(S)
 			skb2 = sock_alloc()
			skb_queue_tail(NS, skb2[V])

			// V became in-flight
			// V count=2 inflight=1

			close(V)

			// V count=1 inflight=1
			// GC candidate condition met

						for u in gc_inflight_list:
						  if (total_refs == inflight_refs)
						    add u to gc_candidates

						// gc_candidates={L, V}

						for u in gc_candidates:
						  scan_children(u, dec_inflight)

						// embryo (skb1) was not
						// reachable from L yet, so V's
						// inflight remains unchanged
__skb_queue_tail(L, skb1)
unix_state_unlock(L)
						for u in gc_candidates:
						  if (u.inflight)
						    scan_children(u, inc_inflight_move_tail)

						// V count=1 inflight=2 (!)

If there is a GC-candidate listening socket, lock/unlock its state. This
makes GC wait until the end of any ongoing connect() to that socket. After
flipping the lock, a possibly SCM-laden embryo is already enqueued. And if
there is another embryo coming, it can not possibly carry SCM_RIGHTS. At
this point, unix_inflight() can not happen because unix_gc_lock is already
taken. Inflight graph remains unaffected.

Fixes: 1fd05ba5a2 ("[AF_UNIX]: Rewrite garbage collector, fixes race.")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240409201047.1032217-1-mhal@rbox.co
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-11 09:46:15 +02:00
Kuniyuki Iwashima
b46f4eaa4f af_unix: Clear stale u->oob_skb.
syzkaller started to report deadlock of unix_gc_lock after commit
4090fa373f ("af_unix: Replace garbage collection algorithm."), but
it just uncovers the bug that has been there since commit 314001f0bf
("af_unix: Add OOB support").

The repro basically does the following.

  from socket import *
  from array import array

  c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
  c1.sendmsg([b'a'], [(SOL_SOCKET, SCM_RIGHTS, array("i", [c2.fileno()]))], MSG_OOB)
  c2.recv(1)  # blocked as no normal data in recv queue

  c2.close()  # done async and unblock recv()
  c1.close()  # done async and trigger GC

A socket sends its file descriptor to itself as OOB data and tries to
receive normal data, but finally recv() fails due to async close().

The problem here is wrong handling of OOB skb in manage_oob().  When
recvmsg() is called without MSG_OOB, manage_oob() is called to check
if the peeked skb is OOB skb.  In such a case, manage_oob() pops it
out of the receive queue but does not clear unix_sock(sk)->oob_skb.
This is wrong in terms of uAPI.

Let's say we send "hello" with MSG_OOB, and "world" without MSG_OOB.
The 'o' is handled as OOB data.  When recv() is called twice without
MSG_OOB, the OOB data should be lost.

  >>> from socket import *
  >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM, 0)
  >>> c1.send(b'hello', MSG_OOB)  # 'o' is OOB data
  5
  >>> c1.send(b'world')
  5
  >>> c2.recv(5)  # OOB data is not received
  b'hell'
  >>> c2.recv(5)  # OOB date is skipped
  b'world'
  >>> c2.recv(5, MSG_OOB)  # This should return an error
  b'o'

In the same situation, TCP actually returns -EINVAL for the last
recv().

Also, if we do not clear unix_sk(sk)->oob_skb, unix_poll() always set
EPOLLPRI even though the data has passed through by previous recv().

To avoid these issues, we must clear unix_sk(sk)->oob_skb when dequeuing
it from recv queue.

The reason why the old GC did not trigger the deadlock is because the
old GC relied on the receive queue to detect the loop.

When it is triggered, the socket with OOB data is marked as GC candidate
because file refcount == inflight count (1).  However, after traversing
all inflight sockets, the socket still has a positive inflight count (1),
thus the socket is excluded from candidates.  Then, the old GC lose the
chance to garbage-collect the socket.

With the old GC, the repro continues to create true garbage that will
never be freed nor detected by kmemleak as it's linked to the global
inflight list.  That's why we couldn't even notice the issue.

Fixes: 314001f0bf ("af_unix: Add OOB support")
Reported-by: syzbot+7f7f201cc2668a8fd169@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240405221057.2406-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-08 19:58:48 -07:00
Kuniyuki Iwashima
118f457da9 af_unix: Remove lock dance in unix_peek_fds().
In the previous GC implementation, the shape of the inflight socket
graph was not expected to change while GC was in progress.

MSG_PEEK was tricky because it could install inflight fd silently
and transform the graph.

Let's say we peeked a fd, which was a listening socket, and accept()ed
some embryo sockets from it.  The garbage collection algorithm would
have been confused because the set of sockets visited in scan_inflight()
would change within the same GC invocation.

That's why we placed spin_lock(&unix_gc_lock) and spin_unlock() in
unix_peek_fds() with a fat comment.

In the new GC implementation, we no longer garbage-collect the socket
if it exists in another queue, that is, if it has a bridge to another
SCC.  Also, accept() will require the lock if it has edges.

Thus, we need not do the complicated lock dance.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240401173125.92184-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-03 19:27:13 -07:00
Kuniyuki Iwashima
7c349ed090 af_unix: Remove scm_fp_dup() in unix_attach_fds().
When we passed fds, we used to bump each file's refcount twice
in scm_fp_copy() and scm_fp_dup() before linking the socket to
gc_inflight_list.

This is because we incremented the inflight count of the socket
and linked it to the list in advance before passing skb to the
destination socket.

Otherwise, the inflight socket could have been garbage-collected
in a small race window between linking the socket to the list and
queuing skb:

  CPU 1 : sendmsg(X) w/ A's fd     CPU 2 : close(A)
  -----                            -----
  /* Here A's refcount is 1, and inflight count is 0 */

  bump A's refcount to 2 in scm_fp_copy()
  bump A's inflight count to 1
  link A to gc_inflight_list
                                   decrement A's refcount to 1

  /* A's refcount == inflight count, thus A could be GC candidate */

                                   start GC
                                   mark A as candidate
                                   purge A's receive queue

  queue skb w/ A's fd to X

  /* A is queued, but all data has been lost */

After commit 4090fa373f ("af_unix: Replace garbage collection
algorithm."), we increment the inflight count and link the socket
to the global list only when queuing the skb.

The race no longer exists, so let's not clone the fd nor bump
the count in unix_attach_fds().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240401173125.92184-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-03 19:27:13 -07:00
Eric Dumazet
1abe267f17 net: add sk_wake_async_rcu() helper
While looking at UDP receive performance, I saw sk_wake_async()
was no longer inlined.

This matters at least on AMD Zen1-4 platforms (see SRSO)

This might be because rcu_read_lock() and rcu_read_unlock()
are no longer nops in recent kernels ?

Add sk_wake_async_rcu() variant, which must be called from
contexts already holding rcu lock.

As SOCK_FASYNC is deprecated in modern days, use unlikely()
to give a hint to the compiler.

sk_wake_async_rcu() is properly inlined from
__udp_enqueue_schedule_skb() and sock_def_readable().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240328144032.1864988-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 15:03:11 -07:00
Kuniyuki Iwashima
4090fa373f af_unix: Replace garbage collection algorithm.
If we find a dead SCC during iteration, we call unix_collect_skb()
to splice all skb in the SCC to the global sk_buff_head, hitlist.

After iterating all SCC, we unlock unix_gc_lock and purge the queue.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-15-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:42 -07:00
Kuniyuki Iwashima
a15702d8b3 af_unix: Detect dead SCC.
When iterating SCC, we call unix_vertex_dead() for each vertex
to check if the vertex is close()d and has no bridge to another
SCC.

If both conditions are true for every vertex in SCC, we can
execute garbage collection for all skb in the SCC.

The actual garbage collection is done in the following patch,
replacing the old implementation.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-14-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:38 -07:00
Kuniyuki Iwashima
bfdb01283e af_unix: Assign a unique index to SCC.
The definition of the lowlink in Tarjan's algorithm is the
smallest index of a vertex that is reachable with at most one
back-edge in SCC.  This is not useful for a cross-edge.

If we start traversing from A in the following graph, the final
lowlink of D is 3.  The cross-edge here is one between D and C.

  A -> B -> D   D = (4, 3)  (index, lowlink)
  ^    |    |   C = (3, 1)
  |    V    |   B = (2, 1)
  `--- C <--'   A = (1, 1)

This is because the lowlink of D is updated with the index of C.

In the following patch, we detect a dead SCC by checking two
conditions for each vertex.

  1) vertex has no edge directed to another SCC (no bridge)
  2) vertex's out_degree is the same as the refcount of its file

If 1) is false, there is a receiver of all fds of the SCC and
its ancestor SCC.

To evaluate 1), we need to assign a unique index to each SCC and
assign it to all vertices in the SCC.

This patch changes the lowlink update logic for cross-edge so
that in the example above, the lowlink of D is updated with the
lowlink of C.

  A -> B -> D   D = (4, 1)  (index, lowlink)
  ^    |    |   C = (3, 1)
  |    V    |   B = (2, 1)
  `--- C <--'   A = (1, 1)

Then, all vertices in the same SCC have the same lowlink, and we
can quickly find the bridge connecting to different SCC if exists.

However, it is no longer called lowlink, so we rename it to
scc_index.  (It's sometimes called lowpoint.)

Also, we add a global variable to hold the last index used in DFS
so that we do not reset the initial index in each DFS.

This patch can be squashed to the SCC detection patch but is
split deliberately for anyone wondering why lowlink is not used
as used in the original Tarjan's algorithm and many reference
implementations.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-13-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:33 -07:00
Kuniyuki Iwashima
ad081928a8 af_unix: Avoid Tarjan's algorithm if unnecessary.
Once a cyclic reference is formed, we need to run GC to check if
there is dead SCC.

However, we do not need to run Tarjan's algorithm if we know that
the shape of the inflight graph has not been changed.

If an edge is added/updated/deleted and the edge's successor is
inflight, we set false to unix_graph_grouped, which means we need
to re-classify SCC.

Once we finalise SCC, we set true to unix_graph_grouped.

While unix_graph_grouped is true, we can iterate the grouped
SCC using vertex->scc_entry in unix_walk_scc_fast().

list_add() and list_for_each_entry_reverse() uses seem weird, but
they are to keep the vertex order consistent and make writing test
easier.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-12-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:29 -07:00
Kuniyuki Iwashima
77e5593aeb af_unix: Skip GC if no cycle exists.
We do not need to run GC if there is no possible cyclic reference.
We use unix_graph_maybe_cyclic to decide if we should run GC.

If a fd of an AF_UNIX socket is passed to an already inflight AF_UNIX
socket, they could form a cyclic reference.  Then, we set true to
unix_graph_maybe_cyclic and later run Tarjan's algorithm to group
them into SCC.

Once we run Tarjan's algorithm, we are 100% sure whether cyclic
references exist or not.  If there is no cycle, we set false to
unix_graph_maybe_cyclic and can skip the entire garbage collection
next time.

When finalising SCC, we set true to unix_graph_maybe_cyclic if SCC
consists of multiple vertices.

Even if SCC is a single vertex, a cycle might exist as self-fd passing.
Given the corner case is rare, we detect it by checking all edges of
the vertex and set true to unix_graph_maybe_cyclic.

With this change, __unix_gc() is just a spin_lock() dance in the normal
usage.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-11-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:25 -07:00
Kuniyuki Iwashima
ba31b4a4e1 af_unix: Save O(n) setup of Tarjan's algo.
Before starting Tarjan's algorithm, we need to mark all vertices
as unvisited.  We can save this O(n) setup by reserving two special
indices (0, 1) and using two variables.

The first time we link a vertex to unix_unvisited_vertices, we set
unix_vertex_unvisited_index to index.

During DFS, we can see that the index of unvisited vertices is the
same as unix_vertex_unvisited_index.

When we finalise SCC later, we set unix_vertex_grouped_index to each
vertex's index.

Then, we can know (i) that the vertex is on the stack if the index
of a visited vertex is >= 2 and (ii) that it is not on the stack and
belongs to a different SCC if the index is unix_vertex_grouped_index.

After the whole algorithm, all indices of vertices are set as
unix_vertex_grouped_index.

Next time we start DFS, we know that all unvisited vertices have
unix_vertex_grouped_index, and we can use unix_vertex_unvisited_index
as the not-on-stack marker.

To use the same variable in __unix_walk_scc(), we can swap
unix_vertex_(grouped|unvisited)_index at the end of Tarjan's
algorithm.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-10-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:20 -07:00
Kuniyuki Iwashima
dcf70df204 af_unix: Fix up unix_edge.successor for embryo socket.
To garbage collect inflight AF_UNIX sockets, we must define the
cyclic reference appropriately.  This is a bit tricky if the loop
consists of embryo sockets.

Suppose that the fd of AF_UNIX socket A is passed to D and the fd B
to C and that C and D are embryo sockets of A and B, respectively.
It may appear that there are two separate graphs, A (-> D) and
B (-> C), but this is not correct.

     A --. .-- B
          X
     C <-' `-> D

Now, D holds A's refcount, and C has B's refcount, so unix_release()
will never be called for A and B when we close() them.  However, no
one can call close() for D and C to free skbs holding refcounts of A
and B because C/D is in A/B's receive queue, which should have been
purged by unix_release() for A and B.

So, here's another type of cyclic reference.  When a fd of an AF_UNIX
socket is passed to an embryo socket, the reference is indirectly held
by its parent listening socket.

  .-> A                            .-> B
  |   `- sk_receive_queue          |   `- sk_receive_queue
  |      `- skb                    |      `- skb
  |         `- sk == C             |         `- sk == D
  |            `- sk_receive_queue |           `- sk_receive_queue
  |               `- skb +---------'               `- skb +-.
  |                                                         |
  `---------------------------------------------------------'

Technically, the graph must be denoted as A <-> B instead of A (-> D)
and B (-> C) to find such a cyclic reference without touching each
socket's receive queue.

  .-> A --. .-- B <-.
  |        X        |  ==  A <-> B
  `-- C <-' `-> D --'

We apply this fixup during GC by fetching the real successor by
unix_edge_successor().

When we call accept(), we clear unix_sock.listener under unix_gc_lock
not to confuse GC.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-9-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:14 -07:00
Kuniyuki Iwashima
aed6ecef55 af_unix: Save listener for embryo socket.
This is a prep patch for the following change, where we need to
fetch the listening socket from the successor embryo socket
during GC.

We add a new field to struct unix_sock to save a pointer to a
listening socket.

We set it when connect() creates a new socket, and clear it when
accept() is called.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:10 -07:00
Kuniyuki Iwashima
3484f06317 af_unix: Detect Strongly Connected Components.
In the new GC, we use a simple graph algorithm, Tarjan's Strongly
Connected Components (SCC) algorithm, to find cyclic references.

The algorithm visits every vertex exactly once using depth-first
search (DFS).

DFS starts by pushing an input vertex to a stack and assigning it
a unique number.  Two fields, index and lowlink, are initialised
with the number, but lowlink could be updated later during DFS.

If a vertex has an edge to an unvisited inflight vertex, we visit
it and do the same processing.  So, we will have vertices in the
stack in the order they appear and number them consecutively in
the same order.

If a vertex has a back-edge to a visited vertex in the stack,
we update the predecessor's lowlink with the successor's index.

After iterating edges from the vertex, we check if its index
equals its lowlink.

If the lowlink is different from the index, it shows there was a
back-edge.  Then, we go backtracking and propagate the lowlink to
its predecessor and resume the previous edge iteration from the
next edge.

If the lowlink is the same as the index, we pop vertices before
and including the vertex from the stack.  Then, the set of vertices
is SCC, possibly forming a cycle.  At the same time, we move the
vertices to unix_visited_vertices.

When we finish the algorithm, all vertices in each SCC will be
linked via unix_vertex.scc_entry.

Let's take an example.  We have a graph including five inflight
vertices (F is not inflight):

  A -> B -> C -> D -> E (-> F)
       ^         |
       `---------'

Suppose that we start DFS from C.  We will visit C, D, and B first
and initialise their index and lowlink.  Then, the stack looks like
this:

  > B = (3, 3)  (index, lowlink)
    D = (2, 2)
    C = (1, 1)

When checking B's edge to C, we update B's lowlink with C's index
and propagate it to D.

    B = (3, 1)  (index, lowlink)
  > D = (2, 1)
    C = (1, 1)

Next, we visit E, which has no edge to an inflight vertex.

  > E = (4, 4)  (index, lowlink)
    B = (3, 1)
    D = (2, 1)
    C = (1, 1)

When we leave from E, its index and lowlink are the same, so we
pop E from the stack as single-vertex SCC.  Next, we leave from
B and D but do nothing because their lowlink are different from
their index.

    B = (3, 1)  (index, lowlink)
    D = (2, 1)
  > C = (1, 1)

Then, we leave from C, whose index and lowlink are the same, so
we pop B, D and C as SCC.

Last, we do DFS for the rest of vertices, A, which is also a
single-vertex SCC.

Finally, each unix_vertex.scc_entry is linked as follows:

  A -.  B -> C -> D  E -.
  ^  |  ^         |  ^  |
  `--'  `---------'  `--'

We use SCC later to decide whether we can garbage-collect the
sockets.

Note that we still cannot detect SCC properly if an edge points
to an embryo socket.  The following two patches will sort it out.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:28:04 -07:00
Kuniyuki Iwashima
6ba76fd284 af_unix: Iterate all vertices by DFS.
The new GC will use a depth first search graph algorithm to find
cyclic references.  The algorithm visits every vertex exactly once.

Here, we implement the DFS part without recursion so that no one
can abuse it.

unix_walk_scc() marks every vertex unvisited by initialising index
as UNIX_VERTEX_INDEX_UNVISITED and iterates inflight vertices in
unix_unvisited_vertices and call __unix_walk_scc() to start DFS from
an arbitrary vertex.

__unix_walk_scc() iterates all edges starting from the vertex and
explores the neighbour vertices with DFS using edge_stack.

After visiting all neighbours, __unix_walk_scc() moves the visited
vertex to unix_visited_vertices so that unix_walk_scc() will not
restart DFS from the visited vertex.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:27:59 -07:00
Kuniyuki Iwashima
22c3c0c52d af_unix: Bulk update unix_tot_inflight/unix_inflight when queuing skb.
Currently, we track the number of inflight sockets in two variables.
unix_tot_inflight is the total number of inflight AF_UNIX sockets on
the host, and user->unix_inflight is the number of inflight fds per
user.

We update them one by one in unix_inflight(), which can be done once
in batch.  Also, sendmsg() could fail even after unix_inflight(), then
we need to acquire unix_gc_lock only to decrement the counters.

Let's bulk update the counters in unix_add_edges() and unix_del_edges(),
which is called only for successfully passed fds.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-5-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:27:55 -07:00
Kuniyuki Iwashima
42f298c06b af_unix: Link struct unix_edge when queuing skb.
Just before queuing skb with inflight fds, we call scm_stat_add(),
which is a good place to set up the preallocated struct unix_vertex
and struct unix_edge in UNIXCB(skb).fp.

Then, we call unix_add_edges() and construct the directed graph
as follows:

  1. Set the inflight socket's unix_sock to unix_edge.predecessor.
  2. Set the receiver's unix_sock to unix_edge.successor.
  3. Set the preallocated vertex to inflight socket's unix_sock.vertex.
  4. Link inflight socket's unix_vertex.entry to unix_unvisited_vertices.
  5. Link unix_edge.vertex_entry to the inflight socket's unix_vertex.edges.

Let's say we pass the fd of AF_UNIX socket A to B and the fd of B
to C.  The graph looks like this:

  +-------------------------+
  | unix_unvisited_vertices | <-------------------------.
  +-------------------------+                           |
  +                                                     |
  |     +--------------+             +--------------+   |         +--------------+
  |     |  unix_sock A | <---. .---> |  unix_sock B | <-|-. .---> |  unix_sock C |
  |     +--------------+     | |     +--------------+   | | |     +--------------+
  | .-+ |    vertex    |     | | .-+ |    vertex    |   | | |     |    vertex    |
  | |   +--------------+     | | |   +--------------+   | | |     +--------------+
  | |                        | | |                      | | |
  | |   +--------------+     | | |   +--------------+   | | |
  | '-> |  unix_vertex |     | | '-> |  unix_vertex |   | | |
  |     +--------------+     | |     +--------------+   | | |
  `---> |    entry     | +---------> |    entry     | +-' | |
        |--------------|     | |     |--------------|     | |
        |    edges     | <-. | |     |    edges     | <-. | |
        +--------------+   | | |     +--------------+   | | |
                           | | |                        | | |
    .----------------------' | | .----------------------' | |
    |                        | | |                        | |
    |   +--------------+     | | |   +--------------+     | |
    |   |   unix_edge  |     | | |   |   unix_edge  |     | |
    |   +--------------+     | | |   +--------------+     | |
    `-> | vertex_entry |     | | `-> | vertex_entry |     | |
        |--------------|     | |     |--------------|     | |
        |  predecessor | +---' |     |  predecessor | +---' |
        |--------------|       |     |--------------|       |
        |   successor  | +-----'     |   successor  | +-----'
        +--------------+             +--------------+

Henceforth, we denote such a graph as A -> B (-> C).

Now, we can express all inflight fd graphs that do not contain
embryo sockets.  We will support the particular case later.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:27:50 -07:00
Kuniyuki Iwashima
29b64e3540 af_unix: Allocate struct unix_edge for each inflight AF_UNIX fd.
As with the previous patch, we preallocate to skb's scm_fp_list an
array of struct unix_edge in the number of inflight AF_UNIX fds.

There we just preallocate memory and do not use immediately because
sendmsg() could fail after this point.  The actual use will be in
the next patch.

When we queue skb with inflight edges, we will set the inflight
socket's unix_sock as unix_edge->predecessor and the receiver's
unix_sock as successor, and then we will link the edge to the
inflight socket's unix_vertex.edges.

Note that we set NULL to cloned scm_fp_list.edges in scm_fp_dup()
so that MSG_PEEK does not change the shape of the directed graph.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:27:44 -07:00
Kuniyuki Iwashima
1fbfdfaa59 af_unix: Allocate struct unix_vertex for each inflight AF_UNIX fd.
We will replace the garbage collection algorithm for AF_UNIX, where
we will consider each inflight AF_UNIX socket as a vertex and its file
descriptor as an edge in a directed graph.

This patch introduces a new struct unix_vertex representing a vertex
in the graph and adds its pointer to struct unix_sock.

When we send a fd using the SCM_RIGHTS message, we allocate struct
scm_fp_list to struct scm_cookie in scm_fp_copy().  Then, we bump
each refcount of the inflight fds' struct file and save them in
scm_fp_list.fp.

After that, unix_attach_fds() inexplicably clones scm_fp_list of
scm_cookie and sets it to skb.  (We will remove this part after
replacing GC.)

Here, we add a new function call in unix_attach_fds() to preallocate
struct unix_vertex per inflight AF_UNIX fd and link each vertex to
skb's scm_fp_list.vertices.

When sendmsg() succeeds later, if the socket of the inflight fd is
still not inflight yet, we will set the preallocated vertex to struct
unix_sock.vertex and link it to a global list unix_unvisited_vertices
under spin_lock(&unix_gc_lock).

If the socket is already inflight, we free the preallocated vertex.
This is to avoid taking the lock unnecessarily when sendmsg() could
fail later.

In the following patch, we will similarly allocate another struct
per edge, which will finally be linked to the inflight socket's
unix_vertex.edges.

And then, we will count the number of edges as unix_vertex.out_degree.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 08:27:33 -07:00
Jakub Kicinski
fecc51559a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/udp.c
  f796feabb9 ("udp: add local "peek offset enabled" flag")
  56667da739 ("net: implement lockless setsockopt(SO_PEEK_OFF)")

Adjacent changes:

net/unix/garbage.c
  aa82ac51d6 ("af_unix: Drop oob_skb ref before purging queue in GC.")
  11498715f2 ("af_unix: Remove io_uring code for GC.")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-22 15:29:26 -08:00
Kuniyuki Iwashima
aa82ac51d6 af_unix: Drop oob_skb ref before purging queue in GC.
syzbot reported another task hung in __unix_gc().  [0]

The current while loop assumes that all of the left candidates
have oob_skb and calling kfree_skb(oob_skb) releases the remaining
candidates.

However, I missed a case that oob_skb has self-referencing fd and
another fd and the latter sk is placed before the former in the
candidate list.  Then, the while loop never proceeds, resulting
the task hung.

__unix_gc() has the same loop just before purging the collected skb,
so we can call kfree_skb(oob_skb) there and let __skb_queue_purge()
release all inflight sockets.

[0]:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2784 Comm: kworker/u4:8 Not tainted 6.8.0-rc4-syzkaller-01028-g71b605d32017 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: events_unbound __unix_gc
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200
Code: 89 fb e8 23 00 00 00 48 8b 3d 84 f5 1a 0c 48 89 de 5b e9 43 26 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d 90 52 70 7e 65 8b 15 91 52 70
RSP: 0018:ffffc9000a17fa78 EFLAGS: 00000287
RAX: ffffffff8a0a6108 RBX: ffff88802b6c2640 RCX: ffff88802c0b3b80
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc9000a17fbf0 R08: ffffffff89383f1d R09: 1ffff1100ee5ff84
R10: dffffc0000000000 R11: ffffed100ee5ff85 R12: 1ffff110056d84ee
R13: ffffc9000a17fae0 R14: 0000000000000000 R15: ffffffff8f47b840
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef5687ff8 CR3: 0000000029b34000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __unix_gc+0xe69/0xf40 net/unix/garbage.c:343
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
 </TASK>

Reported-and-tested-by: syzbot+ecab4d36f920c3574bf9@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ecab4d36f920c3574bf9
Fixes: 25236c91b5 ("af_unix: Fix task hung while purging oob_skb in GC.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-21 12:40:28 +00:00
Eric Dumazet
56667da739 net: implement lockless setsockopt(SO_PEEK_OFF)
syzbot reported a lockdep violation [1] involving af_unix
support of SO_PEEK_OFF.

Since SO_PEEK_OFF is inherently not thread safe (it uses a per-socket
sk_peek_off field), there is really no point to enforce a pointless
thread safety in the kernel.

After this patch :

- setsockopt(SO_PEEK_OFF) no longer acquires the socket lock.

- skb_consume_udp() no longer has to acquire the socket lock.

- af_unix no longer needs a special version of sk_set_peek_off(),
  because it does not lock u->iolock anymore.

As a followup, we could replace prot->set_peek_off to be a boolean
and avoid an indirect call, since we always use sk_set_peek_off().

[1]

WARNING: possible circular locking dependency detected
6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Not tainted

syz-executor.2/30025 is trying to acquire lock:
 ffff8880765e7d80 (&u->iolock){+.+.}-{3:3}, at: unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789

but task is already holding lock:
 ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]
 ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]
 ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_UNIX){+.+.}-{0:0}:
        lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
        lock_sock_nested+0x48/0x100 net/core/sock.c:3524
        lock_sock include/net/sock.h:1691 [inline]
        __unix_dgram_recvmsg+0x1275/0x12c0 net/unix/af_unix.c:2415
        sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046
        ____sys_recvmsg+0x3c0/0x470 net/socket.c:2801
        ___sys_recvmsg net/socket.c:2845 [inline]
        do_recvmmsg+0x474/0xae0 net/socket.c:2939
        __sys_recvmmsg net/socket.c:3018 [inline]
        __do_sys_recvmmsg net/socket.c:3041 [inline]
        __se_sys_recvmmsg net/socket.c:3034 [inline]
        __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034
       do_syscall_64+0xf9/0x240
       entry_SYSCALL_64_after_hwframe+0x6f/0x77

-> #0 (&u->iolock){+.+.}-{3:3}:
        check_prev_add kernel/locking/lockdep.c:3134 [inline]
        check_prevs_add kernel/locking/lockdep.c:3253 [inline]
        validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
        __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
        lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
        __mutex_lock_common kernel/locking/mutex.c:608 [inline]
        __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
        unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789
       sk_setsockopt+0x207e/0x3360
        do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307
        __sys_setsockopt+0x1ad/0x250 net/socket.c:2334
        __do_sys_setsockopt net/socket.c:2343 [inline]
        __se_sys_setsockopt net/socket.c:2340 [inline]
        __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
       do_syscall_64+0xf9/0x240
       entry_SYSCALL_64_after_hwframe+0x6f/0x77

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_UNIX);
                               lock(&u->iolock);
                               lock(sk_lock-AF_UNIX);
  lock(&u->iolock);

 *** DEADLOCK ***

1 lock held by syz-executor.2/30025:
  #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]
  #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]
  #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193

stack backtrace:
CPU: 0 PID: 30025 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
  check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
  check_prev_add kernel/locking/lockdep.c:3134 [inline]
  check_prevs_add kernel/locking/lockdep.c:3253 [inline]
  validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
  __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
  lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
  __mutex_lock_common kernel/locking/mutex.c:608 [inline]
  __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
  unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789
 sk_setsockopt+0x207e/0x3360
  do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307
  __sys_setsockopt+0x1ad/0x250 net/socket.c:2334
  __do_sys_setsockopt net/socket.c:2343 [inline]
  __se_sys_setsockopt net/socket.c:2340 [inline]
  __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f78a1c7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f78a0fde0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f78a1dac050 RCX: 00007f78a1c7dda9
RDX: 000000000000002a RSI: 0000000000000001 RDI: 0000000000000006
RBP: 00007f78a1cca47a R08: 0000000000000004 R09: 0000000000000000
R10: 0000000020000180 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f78a1dac050 R15: 00007ffe5cd81ae8

Fixes: 859051dd16 ("bpf: Implement cgroup sockaddr hooks for unix sockets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Daan De Meyer <daan.j.demeyer@gmail.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-21 11:24:20 +00:00
Jakub Kicinski
73be9a3aab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

net/core/dev.c
  9f30831390 ("net: add rcu safety to rtnl_prop_list_size()")
  723de3ebef ("net: free altname using an RCU callback")

net/unix/garbage.c
  11498715f2 ("af_unix: Remove io_uring code for GC.")
  25236c91b5 ("af_unix: Fix task hung while purging oob_skb in GC.")

drivers/net/ethernet/renesas/ravb_main.c
  ed4adc0720 ("net: ravb: Count packets instead of descriptors in GbEth RX path"
)
  c2da940857 ("ravb: Add Rx checksum offload support for GbEth")

net/mptcp/protocol.c
  bdd70eb689 ("mptcp: drop the push_pending field")
  28e5c13805 ("mptcp: annotate lockless accesses around read-mostly fields")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-15 16:20:04 -08:00
Kuniyuki Iwashima
25236c91b5 af_unix: Fix task hung while purging oob_skb in GC.
syzbot reported a task hung; at the same time, GC was looping infinitely
in list_for_each_entry_safe() for OOB skb.  [0]

syzbot demonstrated that the list_for_each_entry_safe() was not actually
safe in this case.

A single skb could have references for multiple sockets.  If we free such
a skb in the list_for_each_entry_safe(), the current and next sockets could
be unlinked in a single iteration.

unix_notinflight() uses list_del_init() to unlink the socket, so the
prefetched next socket forms a loop itself and list_for_each_entry_safe()
never stops.

Here, we must use while() and make sure we always fetch the first socket.

[0]:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5065 Comm: syz-executor236 Not tainted 6.8.0-rc3-syzkaller-00136-g1f719a2f3fa6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:207
Code: cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 14 25 40 c2 03 00 <65> 8b 05 b4 7c 78 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74
RSP: 0018:ffffc900033efa58 EFLAGS: 00000283
RAX: ffff88807b077800 RBX: ffff88807b077800 RCX: 1ffffffff27b1189
RDX: ffff88802a5a3b80 RSI: ffffffff8968488d RDI: ffff88807b077f70
RBP: ffffc900033efbb0 R08: 0000000000000001 R09: fffffbfff27a900c
R10: ffffffff93d48067 R11: ffffffff8ae000eb R12: ffff88807b077800
R13: dffffc0000000000 R14: ffff88807b077e40 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564f4fc1e3a8 CR3: 000000000d57a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 unix_gc+0x563/0x13b0 net/unix/garbage.c:319
 unix_release_sock+0xa93/0xf80 net/unix/af_unix.c:683
 unix_release+0x91/0xf0 net/unix/af_unix.c:1064
 __sock_release+0xb0/0x270 net/socket.c:659
 sock_close+0x1c/0x30 net/socket.c:1421
 __fput+0x270/0xb80 fs/file_table.c:376
 task_work_run+0x14f/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa8a/0x2ad0 kernel/exit.c:871
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020
 __do_sys_exit_group kernel/exit.c:1031 [inline]
 __se_sys_exit_group kernel/exit.c:1029 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1029
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f9d6cbdac09
Code: Unable to access opcode bytes at 0x7f9d6cbdabdf.
RSP: 002b:00007fff5952feb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9d6cbdac09
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f9d6cc552b0 R08: ffffffffffffffb8 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000246 R12: 00007f9d6cc552b0
R13: 0000000000000000 R14: 00007f9d6cc55d00 R15: 00007f9d6cbabe70
 </TASK>

Reported-by: syzbot+4fa4a2d1f5a5ee06f006@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4fa4a2d1f5a5ee06f006
Fixes: 1279f9d9de ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240209220453.96053-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-13 11:33:04 +01:00
Jakub Kicinski
3be042cf46 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/stmicro/stmmac/common.h
  38cc3c6dcc ("net: stmmac: protect updates of 64-bit statistics counters")
  fd5a6a7131 ("net: stmmac: est: Per Tx-queue error count for HLBF")
  c5c3e1bfc9 ("net: stmmac: Offload queueMaxSDU from tc-taprio")

drivers/net/wireless/microchip/wilc1000/netdev.c
  c901388028 ("wifi: fill in MODULE_DESCRIPTION()s for wilc1000")
  328efda22a ("wifi: wilc1000: do not realloc workqueue everytime an interface is added")

net/unix/garbage.c
  11498715f2 ("af_unix: Remove io_uring code for GC.")
  1279f9d9de ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-08 15:30:33 -08:00
Kuniyuki Iwashima
1279f9d9de af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.
syzbot reported a warning [0] in __unix_gc() with a repro, which
creates a socketpair and sends one socket's fd to itself using the
peer.

  socketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0
  sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\360", iov_len=1}],
          msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET,
                                      cmsg_type=SCM_RIGHTS, cmsg_data=[3]}],
          msg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1

This forms a self-cyclic reference that GC should finally untangle
but does not due to lack of MSG_OOB handling, resulting in memory
leak.

Recently, commit 11498715f2 ("af_unix: Remove io_uring code for
GC.") removed io_uring's dead code in GC and revealed the problem.

The code was executed at the final stage of GC and unconditionally
moved all GC candidates from gc_candidates to gc_inflight_list.
That papered over the reported problem by always making the following
WARN_ON_ONCE(!list_empty(&gc_candidates)) false.

The problem has been there since commit 2aab4b9690 ("af_unix: fix
struct pid leaks in OOB support") added full scm support for MSG_OOB
while fixing another bug.

To fix this problem, we must call kfree_skb() for unix_sk(sk)->oob_skb
if the socket still exists in gc_candidates after purging collected skb.

Then, we need to set NULL to oob_skb before calling kfree_skb() because
it calls last fput() and triggers unix_release_sock(), where we call
duplicate kfree_skb(u->oob_skb) if not NULL.

Note that the leaked socket remained being linked to a global list, so
kmemleak also could not detect it.  We need to check /proc/net/protocol
to notice the unfreed socket.

[0]:
WARNING: CPU: 0 PID: 2863 at net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345
Modules linked in:
CPU: 0 PID: 2863 Comm: kworker/u4:11 Not tainted 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: events_unbound __unix_gc
RIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345
Code: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 <0f> 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8
RSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffc9000b03fc10 RCX: ffffffff816c493e
RDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30
RBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66
R10: 0000000000000003 R11: 0000000000000002 R12: dffffc0000000000
R13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 process_one_work+0x889/0x15e0 kernel/workqueue.c:2633
 process_scheduled_works kernel/workqueue.c:2706 [inline]
 worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787
 kthread+0x2c6/0x3b0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
 </TASK>

Reported-by: syzbot+fa3ef895554bdbfd1183@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fa3ef895554bdbfd1183
Fixes: 2aab4b9690 ("af_unix: fix struct pid leaks in OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240203183149.63573-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-06 18:33:07 -08:00
Jakub Kicinski
cf244463a2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-01 15:12:37 -08:00
Eric Dumazet
4d322dce82 af_unix: fix lockdep positive in sk_diag_dump_icons()
syzbot reported a lockdep splat [1].

Blamed commit hinted about the possible lockdep
violation, and code used unix_state_lock_nested()
in an attempt to silence lockdep.

It is not sufficient, because unix_state_lock_nested()
is already used from unix_state_double_lock().

We need to use a separate subclass.

This patch adds a distinct enumeration to make things
more explicit.

Also use swap() in unix_state_double_lock() as a clean up.

v2: add a missing inline keyword to unix_state_lock_nested()

[1]
WARNING: possible circular locking dependency detected
6.8.0-rc1-syzkaller-00356-g8a696a29c690 #0 Not tainted

syz-executor.1/2542 is trying to acquire lock:
 ffff88808b5df9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: skb_queue_tail+0x36/0x120 net/core/skbuff.c:3863

but task is already holding lock:
 ffff88808b5dfe70 (&u->lock/1){+.+.}-{2:2}, at: unix_dgram_sendmsg+0xfc7/0x2200 net/unix/af_unix.c:2089

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&u->lock/1){+.+.}-{2:2}:
        lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
        _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
        sk_diag_dump_icons net/unix/diag.c:87 [inline]
        sk_diag_fill+0x6ea/0xfe0 net/unix/diag.c:157
        sk_diag_dump net/unix/diag.c:196 [inline]
        unix_diag_dump+0x3e9/0x630 net/unix/diag.c:220
        netlink_dump+0x5c1/0xcd0 net/netlink/af_netlink.c:2264
        __netlink_dump_start+0x5d7/0x780 net/netlink/af_netlink.c:2370
        netlink_dump_start include/linux/netlink.h:338 [inline]
        unix_diag_handler_dump+0x1c3/0x8f0 net/unix/diag.c:319
       sock_diag_rcv_msg+0xe3/0x400
        netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2543
        sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
        netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
        netlink_unicast+0x7e6/0x980 net/netlink/af_netlink.c:1367
        netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1908
        sock_sendmsg_nosec net/socket.c:730 [inline]
        __sock_sendmsg net/socket.c:745 [inline]
        sock_write_iter+0x39a/0x520 net/socket.c:1160
        call_write_iter include/linux/fs.h:2085 [inline]
        new_sync_write fs/read_write.c:497 [inline]
        vfs_write+0xa74/0xca0 fs/read_write.c:590
        ksys_write+0x1a0/0x2c0 fs/read_write.c:643
        do_syscall_x64 arch/x86/entry/common.c:52 [inline]
        do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (rlock-AF_UNIX){+.+.}-{2:2}:
        check_prev_add kernel/locking/lockdep.c:3134 [inline]
        check_prevs_add kernel/locking/lockdep.c:3253 [inline]
        validate_chain+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
        __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
        lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
        __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
        _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
        skb_queue_tail+0x36/0x120 net/core/skbuff.c:3863
        unix_dgram_sendmsg+0x15d9/0x2200 net/unix/af_unix.c:2112
        sock_sendmsg_nosec net/socket.c:730 [inline]
        __sock_sendmsg net/socket.c:745 [inline]
        ____sys_sendmsg+0x592/0x890 net/socket.c:2584
        ___sys_sendmsg net/socket.c:2638 [inline]
        __sys_sendmmsg+0x3b2/0x730 net/socket.c:2724
        __do_sys_sendmmsg net/socket.c:2753 [inline]
        __se_sys_sendmmsg net/socket.c:2750 [inline]
        __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750
        do_syscall_x64 arch/x86/entry/common.c:52 [inline]
        do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&u->lock/1);
                               lock(rlock-AF_UNIX);
                               lock(&u->lock/1);
  lock(rlock-AF_UNIX);

 *** DEADLOCK ***

1 lock held by syz-executor.1/2542:
  #0: ffff88808b5dfe70 (&u->lock/1){+.+.}-{2:2}, at: unix_dgram_sendmsg+0xfc7/0x2200 net/unix/af_unix.c:2089

stack backtrace:
CPU: 1 PID: 2542 Comm: syz-executor.1 Not tainted 6.8.0-rc1-syzkaller-00356-g8a696a29c690 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
  check_noncircular+0x366/0x490 kernel/locking/lockdep.c:2187
  check_prev_add kernel/locking/lockdep.c:3134 [inline]
  check_prevs_add kernel/locking/lockdep.c:3253 [inline]
  validate_chain+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
  __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
  lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
  skb_queue_tail+0x36/0x120 net/core/skbuff.c:3863
  unix_dgram_sendmsg+0x15d9/0x2200 net/unix/af_unix.c:2112
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg net/socket.c:745 [inline]
  ____sys_sendmsg+0x592/0x890 net/socket.c:2584
  ___sys_sendmsg net/socket.c:2638 [inline]
  __sys_sendmmsg+0x3b2/0x730 net/socket.c:2724
  __do_sys_sendmmsg net/socket.c:2753 [inline]
  __se_sys_sendmmsg net/socket.c:2750 [inline]
  __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f26d887cda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f26d95a60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f26d89abf80 RCX: 00007f26d887cda9
RDX: 000000000000003e RSI: 00000000200bd000 RDI: 0000000000000004
RBP: 00007f26d88c947a R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000008c0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f26d89abf80 R15: 00007ffcfe081a68

Fixes: 2aac7a2cb0 ("unix_diag: Pending connections IDs NLA")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240130184235.1620738-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-31 17:51:55 -08:00
Kuniyuki Iwashima
99a7a5b994 af_unix: Remove CONFIG_UNIX_SCM.
Originally, the code related to garbage collection was all in garbage.c.

Commit f4e65870e5 ("net: split out functions related to registering
inflight socket files") moved some functions to scm.c for io_uring and
added CONFIG_UNIX_SCM just in case AF_UNIX was built as module.

However, since commit 97154bcf4d ("af_unix: Kconfig: make CONFIG_UNIX
bool"), AF_UNIX is no longer built separately.  Also, io_uring does not
support SCM_RIGHTS now.

Let's move the functions back to garbage.c

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-31 16:41:16 -08:00
Kuniyuki Iwashima
11498715f2 af_unix: Remove io_uring code for GC.
Since commit 705318a99a ("io_uring/af_unix: disable sending
io_uring over sockets"), io_uring's unix socket cannot be passed
via SCM_RIGHTS, so it does not contribute to cyclic reference and
no longer be candidate for garbage collection.

Also, commit 6e5e6d2749 ("io_uring: drop any code related to
SCM_RIGHTS") cleaned up SCM_RIGHTS code in io_uring.

Let's do it in AF_UNIX as well by reverting commit 0091bfc817
("io_uring/af_unix: defer registered files gc to io_uring release")
and commit 1036908045 ("net: reclaim skb->scm_io_uring bit").

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-31 16:41:16 -08:00
Kuniyuki Iwashima
d0f6dc2634 af_unix: Replace BUG_ON() with WARN_ON_ONCE().
This is a prep patch for the last patch in this series so that
checkpatch will not warn about BUG_ON().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-31 16:41:15 -08:00
Kuniyuki Iwashima
d9f21b3613 af_unix: Try to run GC async.
If more than 16000 inflight AF_UNIX sockets exist and the garbage
collector is not running, unix_(dgram|stream)_sendmsg() call unix_gc().
Also, they wait for unix_gc() to complete.

In unix_gc(), all inflight AF_UNIX sockets are traversed at least once,
and more if they are the GC candidate.  Thus, sendmsg() significantly
slows down with too many inflight AF_UNIX sockets.

However, if a process sends data with no AF_UNIX FD, the sendmsg() call
does not need to wait for GC.  After this change, only the process that
meets the condition below will be blocked under such a situation.

  1) cmsg contains AF_UNIX socket
  2) more than 32 AF_UNIX sent by the same user are still inflight

Note that even a sendmsg() call that does not meet the condition but has
AF_UNIX FD will be blocked later in unix_scm_to_skb() by the spinlock,
but we allow that as a bonus for sane users.

The results below are the time spent in unix_dgram_sendmsg() sending 1
byte of data with no FD 4096 times on a host where 32K inflight AF_UNIX
sockets exist.

Without series: the sane sendmsg() needs to wait gc unreasonably.

  $ sudo /usr/share/bcc/tools/funclatency -p 11165 unix_dgram_sendmsg
  Tracing 1 functions for "unix_dgram_sendmsg"... Hit Ctrl-C to end.
  ^C
       nsecs               : count     distribution
  [...]
      524288 -> 1048575    : 0        |                                        |
     1048576 -> 2097151    : 3881     |****************************************|
     2097152 -> 4194303    : 214      |**                                      |
     4194304 -> 8388607    : 1        |                                        |

  avg = 1825567 nsecs, total: 7477526027 nsecs, count: 4096

With series: the sane sendmsg() can finish much faster.

  $ sudo /usr/share/bcc/tools/funclatency -p 8702  unix_dgram_sendmsg
  Tracing 1 functions for "unix_dgram_sendmsg"... Hit Ctrl-C to end.
  ^C
       nsecs               : count     distribution
  [...]
         128 -> 255        : 0        |                                        |
         256 -> 511        : 4092     |****************************************|
         512 -> 1023       : 2        |                                        |
        1024 -> 2047       : 0        |                                        |
        2048 -> 4095       : 0        |                                        |
        4096 -> 8191       : 1        |                                        |
        8192 -> 16383      : 1        |                                        |

  avg = 410 nsecs, total: 1680510 nsecs, count: 4096

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240123170856.41348-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-26 20:34:25 -08:00
Kuniyuki Iwashima
8b90a9f819 af_unix: Run GC on only one CPU.
If more than 16000 inflight AF_UNIX sockets exist and the garbage
collector is not running, unix_(dgram|stream)_sendmsg() call unix_gc().
Also, they wait for unix_gc() to complete.

In unix_gc(), all inflight AF_UNIX sockets are traversed at least once,
and more if they are the GC candidate.  Thus, sendmsg() significantly
slows down with too many inflight AF_UNIX sockets.

There is a small window to invoke multiple unix_gc() instances, which
will then be blocked by the same spinlock except for one.

Let's convert unix_gc() to use struct work so that it will not consume
CPUs unnecessarily.

Note WRITE_ONCE(gc_in_progress, true) is moved before running GC.
If we leave the WRITE_ONCE() as is and use the following test to
call flush_work(), a process might not call it.

    CPU 0                                     CPU 1
    ---                                       ---
                                              start work and call __unix_gc()
    if (work_pending(&unix_gc_work) ||        <-- false
        READ_ONCE(gc_in_progress))            <-- false
            flush_work();                     <-- missed!
	                                      WRITE_ONCE(gc_in_progress, true)

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240123170856.41348-5-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-26 20:34:25 -08:00
Kuniyuki Iwashima
5b17307bd0 af_unix: Return struct unix_sock from unix_get_socket().
Currently, unix_get_socket() returns struct sock, but after calling
it, we always cast it to unix_sk().

Let's return struct unix_sock from unix_get_socket().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240123170856.41348-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-26 20:34:25 -08:00
Kuniyuki Iwashima
97af84a6bb af_unix: Do not use atomic ops for unix_sk(sk)->inflight.
When touching unix_sk(sk)->inflight, we are always under
spin_lock(&unix_gc_lock).

Let's convert unix_sk(sk)->inflight to the normal unsigned long.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240123170856.41348-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-26 20:34:24 -08:00
Kuniyuki Iwashima
31e0320711 af_unix: Annotate data-race of gc_in_progress in wait_for_unix_gc().
gc_in_progress is changed under spin_lock(&unix_gc_lock),
but wait_for_unix_gc() reads it locklessly.

Let's use READ_ONCE().

Fixes: 5f23b73496 ("net: Fix soft lockups/OOM issues w/ unix garbage collector")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240123170856.41348-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-26 20:34:24 -08:00
Eric Dumazet
114b4bb1cc sock_diag: add module pointer to "struct sock_diag_handler"
Following patch is going to use RCU instead of
sock_diag_table_mutex acquisition.

This patch is a preparation, no change of behavior yet.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-01-23 15:13:54 +01:00
Linus Torvalds
4c72e2b8c4 for-6.8/io_uring-2024-01-08
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Merge tag 'for-6.8/io_uring-2024-01-08' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:
 "Mostly just come fixes and cleanups, but one feature as well. In
  detail:

   - Harden the check for handling IOPOLL based on return (Pavel)

   - Various minor optimizations (Pavel)

   - Drop remnants of SCM_RIGHTS fd passing support, now that it's no
     longer supported since 6.7 (me)

   - Fix for a case where bytes_done wasn't initialized properly on a
     failure condition for read/write requests (me)

   - Move the register related code to a separate file (me)

   - Add support for returning the provided ring buffer head (me)

   - Add support for adding a direct descriptor to the normal file table
     (me, Christian Brauner)

   - Fix for ensuring pending task_work for a ring with DEFER_TASKRUN is
     run even if we timeout waiting (me)"

* tag 'for-6.8/io_uring-2024-01-08' of git://git.kernel.dk/linux:
  io_uring: ensure local task_work is run on wait timeout
  io_uring/kbuf: add method for returning provided buffer ring head
  io_uring/rw: ensure io->bytes_done is always initialized
  io_uring: drop any code related to SCM_RIGHTS
  io_uring/unix: drop usage of io_uring socket
  io_uring/register: move io_uring_register(2) related code to register.c
  io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL
  io_uring/cmd: inline io_uring_cmd_get_task
  io_uring/cmd: inline io_uring_cmd_do_in_task_lazy
  io_uring: split out cmd api into a separate header
  io_uring: optimise ltimeout for inline execution
  io_uring: don't check iopoll if request completes
2024-01-11 14:19:23 -08:00
John Fastabend
16b2f26498 bpf: sockmap, fix proto update hook to avoid dup calls
When sockets are added to a sockmap or sockhash we allocate and init a
psock. Then update the proto ops with sock_map_init_proto the flow is

  sock_hash_update_common
    sock_map_link
      psock = sock_map_psock_get_checked() <-returns existing psock
      sock_map_init_proto(sk, psock)       <- updates sk_proto

If the socket is already in a map this results in the sock_map_init_proto
being called multiple times on the same socket. We do this because when
a socket is added to multiple maps this might result in a new set of BPF
programs being attached to the socket requiring an updated ops struct.

This creates a rule where it must be safe to call psock_update_sk_prot
multiple times. When we added a fix for UAF through unix sockets in patch
4dd9a38a753fc we broke this rule by adding a sock_hold in that path
to ensure the sock is not released. The result is if a af_unix stream sock
is placed in multiple maps it results in a memory leak because we call
sock_hold multiple times with only a single sock_put on it.

Fixes: 8866730aed ("bpf, sockmap: af_unix stream sockets need to hold ref for pair sock")
Reported-by: Xingwei Lee <xrivendell7@gmail.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20231221232327.43678-2-john.fastabend@gmail.com
2024-01-03 16:50:06 -08:00
Jens Axboe
a4104821ad io_uring/unix: drop usage of io_uring socket
Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-19 12:33:50 -07:00
John Fastabend
8866730aed bpf, sockmap: af_unix stream sockets need to hold ref for pair sock
AF_UNIX stream sockets are a paired socket. So sending on one of the pairs
will lookup the paired socket as part of the send operation. It is possible
however to put just one of the pairs in a BPF map. This currently increments
the refcnt on the sock in the sockmap to ensure it is not free'd by the
stack before sockmap cleans up its state and stops any skbs being sent/recv'd
to that socket.

But we missed a case. If the peer socket is closed it will be free'd by the
stack. However, the paired socket can still be referenced from BPF sockmap
side because we hold a reference there. Then if we are sending traffic through
BPF sockmap to that socket it will try to dereference the free'd pair in its
send logic creating a use after free. And following splat:

   [59.900375] BUG: KASAN: slab-use-after-free in sk_wake_async+0x31/0x1b0
   [59.901211] Read of size 8 at addr ffff88811acbf060 by task kworker/1:2/954
   [...]
   [59.905468] Call Trace:
   [59.905787]  <TASK>
   [59.906066]  dump_stack_lvl+0x130/0x1d0
   [59.908877]  print_report+0x16f/0x740
   [59.910629]  kasan_report+0x118/0x160
   [59.912576]  sk_wake_async+0x31/0x1b0
   [59.913554]  sock_def_readable+0x156/0x2a0
   [59.914060]  unix_stream_sendmsg+0x3f9/0x12a0
   [59.916398]  sock_sendmsg+0x20e/0x250
   [59.916854]  skb_send_sock+0x236/0xac0
   [59.920527]  sk_psock_backlog+0x287/0xaa0

To fix let BPF sockmap hold a refcnt on both the socket in the sockmap and its
paired socket. It wasn't obvious how to contain the fix to bpf_unix logic. The
primarily problem with keeping this logic in bpf_unix was: In the sock close()
we could handle the deref by having a close handler. But, when we are destroying
the psock through a map delete operation we wouldn't have gotten any signal
thorugh the proto struct other than it being replaced. If we do the deref from
the proto replace its too early because we need to deref the sk_pair after the
backlog worker has been stopped.

Given all this it seems best to just cache it at the end of the psock and eat 8B
for the af_unix and vsock users. Notice dgram sockets are OK because they handle
locking already.

Fixes: 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20231129012557.95371-2-john.fastabend@gmail.com
2023-11-30 00:25:16 +01:00
Jakub Kicinski
938dbead34 net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules
W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to all the sock diag modules in one fell swoop.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-19 20:09:13 +00:00
Eric Dumazet
4b7b492615 af_unix: fix use-after-free in unix_stream_read_actor()
syzbot reported the following crash [1]

After releasing unix socket lock, u->oob_skb can be changed
by another thread. We must temporarily increase skb refcount
to make sure this other thread will not free the skb under us.

[1]

BUG: KASAN: slab-use-after-free in unix_stream_read_actor+0xa7/0xc0 net/unix/af_unix.c:2866
Read of size 4 at addr ffff88801f3b9cc4 by task syz-executor107/5297

CPU: 1 PID: 5297 Comm: syz-executor107 Not tainted 6.6.0-syzkaller-15910-gb8e3a87a627b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:475
kasan_report+0xda/0x110 mm/kasan/report.c:588
unix_stream_read_actor+0xa7/0xc0 net/unix/af_unix.c:2866
unix_stream_recv_urg net/unix/af_unix.c:2587 [inline]
unix_stream_read_generic+0x19a5/0x2480 net/unix/af_unix.c:2666
unix_stream_recvmsg+0x189/0x1b0 net/unix/af_unix.c:2903
sock_recvmsg_nosec net/socket.c:1044 [inline]
sock_recvmsg+0xe2/0x170 net/socket.c:1066
____sys_recvmsg+0x21f/0x5c0 net/socket.c:2803
___sys_recvmsg+0x115/0x1a0 net/socket.c:2845
__sys_recvmsg+0x114/0x1e0 net/socket.c:2875
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fc67492c559
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc6748ab228 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 000000000000001c RCX: 00007fc67492c559
RDX: 0000000040010083 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007fc6749b6348 R08: 00007fc6748ab6c0 R09: 00007fc6748ab6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc6749b6340
R13: 00007fc6749b634c R14: 00007ffe9fac52a0 R15: 00007ffe9fac5388
</TASK>

Allocated by task 5295:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:763 [inline]
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x180/0x3c0 mm/slub.c:3523
__alloc_skb+0x287/0x330 net/core/skbuff.c:641
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6331
sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2780
sock_alloc_send_skb include/net/sock.h:1884 [inline]
queue_oob net/unix/af_unix.c:2147 [inline]
unix_stream_sendmsg+0xb5f/0x10a0 net/unix/af_unix.c:2301
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
____sys_sendmsg+0x6ac/0x940 net/socket.c:2584
___sys_sendmsg+0x135/0x1d0 net/socket.c:2638
__sys_sendmsg+0x117/0x1e0 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Freed by task 5295:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1800 [inline]
slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826
slab_free mm/slub.c:3809 [inline]
kmem_cache_free+0xf8/0x340 mm/slub.c:3831
kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:1015
__kfree_skb net/core/skbuff.c:1073 [inline]
consume_skb net/core/skbuff.c:1288 [inline]
consume_skb+0xdf/0x170 net/core/skbuff.c:1282
queue_oob net/unix/af_unix.c:2178 [inline]
unix_stream_sendmsg+0xd49/0x10a0 net/unix/af_unix.c:2301
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
____sys_sendmsg+0x6ac/0x940 net/socket.c:2584
___sys_sendmsg+0x135/0x1d0 net/socket.c:2638
__sys_sendmsg+0x117/0x1e0 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

The buggy address belongs to the object at ffff88801f3b9c80
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 68 bytes inside of
freed 240-byte region [ffff88801f3b9c80, ffff88801f3b9d70)

The buggy address belongs to the physical page:
page:ffffea00007cee40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f3b9
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888142a60640 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5299, tgid 5283 (syz-executor107), ts 103803840339, free_ts 103600093431
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1537
prep_new_page mm/page_alloc.c:1544 [inline]
get_page_from_freelist+0xa25/0x36c0 mm/page_alloc.c:3312
__alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4568
alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
alloc_slab_page mm/slub.c:1870 [inline]
allocate_slab+0x251/0x380 mm/slub.c:2017
new_slab mm/slub.c:2070 [inline]
___slab_alloc+0x8c7/0x1580 mm/slub.c:3223
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322
__slab_alloc_node mm/slub.c:3375 [inline]
slab_alloc_node mm/slub.c:3468 [inline]
kmem_cache_alloc_node+0x132/0x3c0 mm/slub.c:3523
__alloc_skb+0x287/0x330 net/core/skbuff.c:641
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6331
sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2780
sock_alloc_send_skb include/net/sock.h:1884 [inline]
queue_oob net/unix/af_unix.c:2147 [inline]
unix_stream_sendmsg+0xb5f/0x10a0 net/unix/af_unix.c:2301
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
____sys_sendmsg+0x6ac/0x940 net/socket.c:2584
___sys_sendmsg+0x135/0x1d0 net/socket.c:2638
__sys_sendmsg+0x117/0x1e0 net/socket.c:2667
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1137 [inline]
free_unref_page_prepare+0x4f8/0xa90 mm/page_alloc.c:2347
free_unref_page+0x33/0x3b0 mm/page_alloc.c:2487
__unfreeze_partials+0x21d/0x240 mm/slub.c:2655
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:763 [inline]
slab_alloc_node mm/slub.c:3478 [inline]
slab_alloc mm/slub.c:3486 [inline]
__kmem_cache_alloc_lru mm/slub.c:3493 [inline]
kmem_cache_alloc+0x15d/0x380 mm/slub.c:3502
vm_area_dup+0x21/0x2f0 kernel/fork.c:500
__split_vma+0x17d/0x1070 mm/mmap.c:2365
split_vma mm/mmap.c:2437 [inline]
vma_modify+0x25d/0x450 mm/mmap.c:2472
vma_modify_flags include/linux/mm.h:3271 [inline]
mprotect_fixup+0x228/0xc80 mm/mprotect.c:635
do_mprotect_pkey+0x852/0xd60 mm/mprotect.c:809
__do_sys_mprotect mm/mprotect.c:830 [inline]
__se_sys_mprotect mm/mprotect.c:827 [inline]
__x64_sys_mprotect+0x78/0xb0 mm/mprotect.c:827
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Memory state around the buggy address:
ffff88801f3b9b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801f3b9c00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff88801f3b9c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801f3b9d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff88801f3b9d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb

Fixes: 876c14ad01 ("af_unix: fix holding spinlock in oob handling")
Reported-and-tested-by: syzbot+7a2d546fa43e49315ed3@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Rao Shoaib <rao.shoaib@oracle.com>
Reviewed-by: Rao shoaib <rao.shoaib@oracle.com>
Link: https://lore.kernel.org/r/20231113134938.168151-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-11-14 10:51:13 +01:00
Kuniyuki Iwashima
3a04927f8d af_unix: Remove module remnants.
Since commit 97154bcf4d ("af_unix: Kconfig: make CONFIG_UNIX bool"),
af_unix.c is no longer built as module.

Let's remove unnecessary #if condition, exitcall, and module macros.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20231026212305.45545-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-27 09:12:47 -07:00
Daan De Meyer
859051dd16 bpf: Implement cgroup sockaddr hooks for unix sockets
These hooks allows intercepting connect(), getsockname(),
getpeername(), sendmsg() and recvmsg() for unix sockets. The unix
socket hooks get write access to the address length because the
address length is not fixed when dealing with unix sockets and
needs to be modified when a unix socket address is modified by
the hook. Because abstract socket unix addresses start with a
NUL byte, we cannot recalculate the socket address in kernelspace
after running the hook by calculating the length of the unix socket
path using strlen().

These hooks can be used when users want to multiplex syscall to a
single unix socket to multiple different processes behind the scenes
by redirecting the connect() and other syscalls to process specific
sockets.

We do not implement support for intercepting bind() because when
using bind() with unix sockets with a pathname address, this creates
an inode in the filesystem which must be cleaned up. If we rewrite
the address, the user might try to clean up the wrong file, leaking
the socket in the filesystem where it is never cleaned up. Until we
figure out a solution for this (and a use case for intercepting bind()),
we opt to not allow rewriting the sockaddr in bind() calls.

We also implement recvmsg() support for connected streams so that
after a connect() that is modified by a sockaddr hook, any corresponding
recmvsg() on the connected socket can also be modified to make the
connected program think it is connected to the "intended" remote.

Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Link: https://lore.kernel.org/r/20231011185113.140426-5-daan.j.demeyer@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-11 17:27:47 -07:00
Linus Torvalds
73be7fb14e Including fixes from netfilter and bpf.
Current release - regressions:
 
  - eth: stmmac: fix failure to probe without MAC interface specified
 
 Current release - new code bugs:
 
  - docs: netlink: fix missing classic_netlink doc reference
 
 Previous releases - regressions:
 
  - deal with integer overflows in kmalloc_reserve()
 
  - use sk_forward_alloc_get() in sk_get_meminfo()
 
  - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc
 
  - fib: avoid warn splat in flow dissector after packet mangling
 
  - skb_segment: call zero copy functions before using skbuff frags
 
  - eth: sfc: check for zero length in EF10 RX prefix
 
 Previous releases - always broken:
 
  - af_unix: fix msg_controllen test in scm_pidfd_recv() for
    MSG_CMSG_COMPAT
 
  - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR()
 
  - netfilter:
    - nft_exthdr: fix non-linear header modification
    - xt_u32, xt_sctp: validate user space input
    - nftables: exthdr: fix 4-byte stack OOB write
    - nfnetlink_osf: avoid OOB read
    - one more fix for the garbage collection work from last release
 
  - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU
 
  - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t
 
  - handshake: fix null-deref in handshake_nl_done_doit()
 
  - ip: ignore dst hint for multipath routes to ensure packets
    are hashed across the nexthops
 
  - phy: micrel:
    - correct bit assignments for cable test errata
    - disable EEE according to the KSZ9477 errata
 
 Misc:
 
  - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations
 
  - Revert "net: macsec: preserve ingress frame ordering", it appears
    to have been developed against an older kernel, problem doesn't
    exist upstream
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking updates from Jakub Kicinski:
 "Including fixes from netfilter and bpf.

  Current release - regressions:

   - eth: stmmac: fix failure to probe without MAC interface specified

  Current release - new code bugs:

   - docs: netlink: fix missing classic_netlink doc reference

  Previous releases - regressions:

   - deal with integer overflows in kmalloc_reserve()

   - use sk_forward_alloc_get() in sk_get_meminfo()

   - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc

   - fib: avoid warn splat in flow dissector after packet mangling

   - skb_segment: call zero copy functions before using skbuff frags

   - eth: sfc: check for zero length in EF10 RX prefix

  Previous releases - always broken:

   - af_unix: fix msg_controllen test in scm_pidfd_recv() for
     MSG_CMSG_COMPAT

   - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR()

   - netfilter:
      - nft_exthdr: fix non-linear header modification
      - xt_u32, xt_sctp: validate user space input
      - nftables: exthdr: fix 4-byte stack OOB write
      - nfnetlink_osf: avoid OOB read
      - one more fix for the garbage collection work from last release

   - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU

   - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t

   - handshake: fix null-deref in handshake_nl_done_doit()

   - ip: ignore dst hint for multipath routes to ensure packets are
     hashed across the nexthops

   - phy: micrel:
      - correct bit assignments for cable test errata
      - disable EEE according to the KSZ9477 errata

  Misc:

   - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations

   - Revert "net: macsec: preserve ingress frame ordering", it appears
     to have been developed against an older kernel, problem doesn't
     exist upstream"

* tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (95 commits)
  net: enetc: distinguish error from valid pointers in enetc_fixup_clear_rss_rfs()
  Revert "net: team: do not use dynamic lockdep key"
  net: hns3: remove GSO partial feature bit
  net: hns3: fix the port information display when sfp is absent
  net: hns3: fix invalid mutex between tc qdisc and dcb ets command issue
  net: hns3: fix debugfs concurrency issue between kfree buffer and read
  net: hns3: fix byte order conversion issue in hclge_dbg_fd_tcam_read()
  net: hns3: Support query tx timeout threshold by debugfs
  net: hns3: fix tx timeout issue
  net: phy: Provide Module 4 KSZ9477 errata (DS80000754C)
  netfilter: nf_tables: Unbreak audit log reset
  netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c
  netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction
  netfilter: nf_tables: uapi: Describe NFTA_RULE_CHAIN_ID
  netfilter: nfnetlink_osf: avoid OOB read
  netfilter: nftables: exthdr: fix 4-byte stack OOB write
  selftests/bpf: Check bpf_sk_storage has uncharged sk_omem_alloc
  bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc
  bpf: bpf_sk_storage: Fix invalid wait context lockdep report
  s390/bpf: Pass through tail call counter in trampolines
  ...
2023-09-07 18:33:07 -07:00
Kuniyuki Iwashima
ade32bd8a7 af_unix: Fix data-race around unix_tot_inflight.
unix_tot_inflight is changed under spin_lock(unix_gc_lock), but
unix_release_sock() reads it locklessly.

Let's use READ_ONCE() for unix_tot_inflight.

Note that the writer side was marked by commit 9d6d7f1cb6 ("af_unix:
annote lockless accesses to unix_tot_inflight & gc_in_progress")

BUG: KCSAN: data-race in unix_inflight / unix_release_sock

write (marked) to 0xffffffff871852b8 of 4 bytes by task 123 on cpu 1:
 unix_inflight+0x130/0x180 net/unix/scm.c:64
 unix_attach_fds+0x137/0x1b0 net/unix/scm.c:123
 unix_scm_to_skb net/unix/af_unix.c:1832 [inline]
 unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1955
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x148/0x160 net/socket.c:747
 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2493
 ___sys_sendmsg+0xc6/0x140 net/socket.c:2547
 __sys_sendmsg+0x94/0x140 net/socket.c:2576
 __do_sys_sendmsg net/socket.c:2585 [inline]
 __se_sys_sendmsg net/socket.c:2583 [inline]
 __x64_sys_sendmsg+0x45/0x50 net/socket.c:2583
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffffffff871852b8 of 4 bytes by task 4891 on cpu 0:
 unix_release_sock+0x608/0x910 net/unix/af_unix.c:671
 unix_release+0x59/0x80 net/unix/af_unix.c:1058
 __sock_release+0x7d/0x170 net/socket.c:653
 sock_close+0x19/0x30 net/socket.c:1385
 __fput+0x179/0x5e0 fs/file_table.c:321
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x116/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297
 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4891 Comm: systemd-coredum Not tainted 6.4.0-rc5-01219-gfa0e21fa4443 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 9305cfa444 ("[AF_UNIX]: Make unix_tot_inflight counter non-atomic")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-04 11:06:16 +01:00
Kuniyuki Iwashima
0bc36c0650 af_unix: Fix data-races around user->unix_inflight.
user->unix_inflight is changed under spin_lock(unix_gc_lock),
but too_many_unix_fds() reads it locklessly.

Let's annotate the write/read accesses to user->unix_inflight.

BUG: KCSAN: data-race in unix_attach_fds / unix_inflight

write to 0xffffffff8546f2d0 of 8 bytes by task 44798 on cpu 1:
 unix_inflight+0x157/0x180 net/unix/scm.c:66
 unix_attach_fds+0x147/0x1e0 net/unix/scm.c:123
 unix_scm_to_skb net/unix/af_unix.c:1827 [inline]
 unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950
 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline]
 unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292
 sock_sendmsg_nosec net/socket.c:725 [inline]
 sock_sendmsg+0x148/0x160 net/socket.c:748
 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494
 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548
 __sys_sendmsg+0x94/0x140 net/socket.c:2577
 __do_sys_sendmsg net/socket.c:2586 [inline]
 __se_sys_sendmsg net/socket.c:2584 [inline]
 __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

read to 0xffffffff8546f2d0 of 8 bytes by task 44814 on cpu 0:
 too_many_unix_fds net/unix/scm.c:101 [inline]
 unix_attach_fds+0x54/0x1e0 net/unix/scm.c:110
 unix_scm_to_skb net/unix/af_unix.c:1827 [inline]
 unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950
 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline]
 unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292
 sock_sendmsg_nosec net/socket.c:725 [inline]
 sock_sendmsg+0x148/0x160 net/socket.c:748
 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494
 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548
 __sys_sendmsg+0x94/0x140 net/socket.c:2577
 __do_sys_sendmsg net/socket.c:2586 [inline]
 __se_sys_sendmsg net/socket.c:2584 [inline]
 __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

value changed: 0x000000000000000c -> 0x000000000000000d

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 44814 Comm: systemd-coredum Not tainted 6.4.0-11989-g6843306689af #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 712f4aad40 ("unix: properly account for FDs passed over unix sockets")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-04 11:06:16 +01:00
Linus Torvalds
adfd671676 sysctl-6.6-rc1
Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and
 placings sysctls to their own sybsystem or file to help avoid merge conflicts.
 Matthew Wilcox pointed out though that if we're going to do that we might as
 well also *save* space while at it and try to remove the extra last sysctl
 entry added at the end of each array, a sentintel, instead of bloating the
 kernel by adding a new sentinel with each array moved.
 
 Doing that was not so trivial, and has required slowing down the moves of
 kernel/sysctl.c arrays and measuring the impact on size by each new move.
 
 The complex part of the effort to help reduce the size of each sysctl is being
 done by the patient work of el señor Don Joel Granados. A lot of this is truly
 painful code refactoring and testing and then trying to measure the savings of
 each move and removing the sentinels. Although Joel already has code which does
 most of this work, experience with sysctl moves in the past shows is we need to
 be careful due to the slew of odd build failures that are possible due to the
 amount of random Kconfig options sysctls use.
 
 To that end Joel's work is split by first addressing the major housekeeping
 needed to remove the sentinels, which is part of this merge request. The rest
 of the work to actually remove the sentinels will be done later in future
 kernel releases.
 
 At first I was only going to send his first 7 patches of his patch series,
 posted 1 month ago, but in retrospect due to the testing the changes have
 received in linux-next and the minor changes they make this goes with the
 entire set of patches Joel had planned: just sysctl house keeping. There are
 networking changes but these are part of the house keeping too.
 
 The preliminary math is showing this will all help reduce the overall build
 time size of the kernel and run time memory consumed by the kernel by about
 ~64 bytes per array where we are able to remove each sentinel in the future.
 That also means there is no more bloating the kernel with the extra ~64 bytes
 per array moved as no new sentinels are created.
 
 Most of this has been in linux-next for about a month, the last 7 patches took
 a minor refresh 2 week ago based on feedback.
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Merge tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "Long ago we set out to remove the kitchen sink on kernel/sysctl.c
  arrays and placings sysctls to their own sybsystem or file to help
  avoid merge conflicts. Matthew Wilcox pointed out though that if we're
  going to do that we might as well also *save* space while at it and
  try to remove the extra last sysctl entry added at the end of each
  array, a sentintel, instead of bloating the kernel by adding a new
  sentinel with each array moved.

  Doing that was not so trivial, and has required slowing down the moves
  of kernel/sysctl.c arrays and measuring the impact on size by each new
  move.

  The complex part of the effort to help reduce the size of each sysctl
  is being done by the patient work of el señor Don Joel Granados. A lot
  of this is truly painful code refactoring and testing and then trying
  to measure the savings of each move and removing the sentinels.
  Although Joel already has code which does most of this work,
  experience with sysctl moves in the past shows is we need to be
  careful due to the slew of odd build failures that are possible due to
  the amount of random Kconfig options sysctls use.

  To that end Joel's work is split by first addressing the major
  housekeeping needed to remove the sentinels, which is part of this
  merge request. The rest of the work to actually remove the sentinels
  will be done later in future kernel releases.

  The preliminary math is showing this will all help reduce the overall
  build time size of the kernel and run time memory consumed by the
  kernel by about ~64 bytes per array where we are able to remove each
  sentinel in the future. That also means there is no more bloating the
  kernel with the extra ~64 bytes per array moved as no new sentinels
  are created"

* tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  sysctl: Use ctl_table_size as stopping criteria for list macro
  sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl
  vrf: Update to register_net_sysctl_sz
  networking: Update to register_net_sysctl_sz
  netfilter: Update to register_net_sysctl_sz
  ax.25: Update to register_net_sysctl_sz
  sysctl: Add size to register_net_sysctl function
  sysctl: Add size arg to __register_sysctl_init
  sysctl: Add size to register_sysctl
  sysctl: Add a size arg to __register_sysctl_table
  sysctl: Add size argument to init_header
  sysctl: Add ctl_table_size to ctl_table_header
  sysctl: Use ctl_table_header in list_for_each_table_entry
  sysctl: Prefer ctl_table_header in proc_sysctl
2023-08-29 17:39:15 -07:00
Joel Granados
c899710fe7 networking: Update to register_net_sysctl_sz
Move from register_net_sysctl to register_net_sysctl_sz for all the
networking related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

An additional size function was added to the following files in order to
calculate the size of an array that is defined in another file:
    include/net/ipv6.h
    net/ipv6/icmp.c
    net/ipv6/route.c
    net/ipv6/sysctl_net_ipv6.c

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:18 -07:00
Eric Dumazet
1ded5e5a59 net: annotate data-races around sock->ops
IPV6_ADDRFORM socket option is evil, because it can change sock->ops
while other threads might read it. Same issue for sk->sk_family
being set to AF_INET.

Adding READ_ONCE() over sock->ops reads is needed for sockets
that might be impacted by IPV6_ADDRFORM.

Note that mptcp_is_tcpsk() can also overwrite sock->ops.

Adding annotations for all sk->sk_family reads will require
more patches :/

BUG: KCSAN: data-race in ____sys_sendmsg / do_ipv6_setsockopt

write to 0xffff888109f24ca0 of 8 bytes by task 4470 on cpu 0:
do_ipv6_setsockopt+0x2c5e/0x2ce0 net/ipv6/ipv6_sockglue.c:491
ipv6_setsockopt+0x57/0x130 net/ipv6/ipv6_sockglue.c:1012
udpv6_setsockopt+0x95/0xa0 net/ipv6/udp.c:1690
sock_common_setsockopt+0x61/0x70 net/core/sock.c:3663
__sys_setsockopt+0x1c3/0x230 net/socket.c:2273
__do_sys_setsockopt net/socket.c:2284 [inline]
__se_sys_setsockopt net/socket.c:2281 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2281
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888109f24ca0 of 8 bytes by task 4469 on cpu 1:
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x349/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmmsg+0x263/0x500 net/socket.c:2643
__do_sys_sendmmsg net/socket.c:2672 [inline]
__se_sys_sendmmsg net/socket.c:2669 [inline]
__x64_sys_sendmmsg+0x57/0x60 net/socket.c:2669
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffffffff850e32b8 -> 0xffffffff850da890

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4469 Comm: syz-executor.1 Not tainted 6.4.0-rc5-syzkaller-00313-g4c605260bc60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230808135809.2300241-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 15:32:43 -07:00
Eric Dumazet
11695c6e96 net: add missing data-race annotations around sk->sk_peek_off
sk_getsockopt() runs locklessly, thus we need to annotate the read
of sk->sk_peek_off.

While we are at it, add corresponding annotations to sk_set_peek_off()
and unix_set_peek_off().

Fixes: b9bb53f383 ("sock: convert sk_peek_offset functions to WRITE_ONCE")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-29 18:13:41 +01:00
Kuniyuki Iwashima
ecb4534b6a af_unix: Terminate sun_path when bind()ing pathname socket.
kernel test robot reported slab-out-of-bounds access in strlen(). [0]

Commit 06d4c8a808 ("af_unix: Fix fortify_panic() in unix_bind_bsd().")
removed unix_mkname_bsd() call in unix_bind_bsd().

If sunaddr->sun_path is not terminated by user and we don't enable
CONFIG_INIT_STACK_ALL_ZERO=y, strlen() will do the out-of-bounds access
during file creation.

Let's go back to strlen()-with-sockaddr_storage way and pack all 108
trickiness into unix_mkname_bsd() with bold comments.

[0]:
BUG: KASAN: slab-out-of-bounds in strlen (lib/string.c:?)
Read of size 1 at addr ffff000015492777 by task fortify_strlen_/168

CPU: 0 PID: 168 Comm: fortify_strlen_ Not tainted 6.5.0-rc1-00333-g3329b603ebba #16
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace (arch/arm64/kernel/stacktrace.c:235)
 show_stack (arch/arm64/kernel/stacktrace.c:242)
 dump_stack_lvl (lib/dump_stack.c:107)
 print_report (mm/kasan/report.c:365 mm/kasan/report.c:475)
 kasan_report (mm/kasan/report.c:590)
 __asan_report_load1_noabort (mm/kasan/report_generic.c:378)
 strlen (lib/string.c:?)
 getname_kernel (./include/linux/fortify-string.h:? fs/namei.c:226)
 kern_path_create (fs/namei.c:3926)
 unix_bind (net/unix/af_unix.c:1221 net/unix/af_unix.c:1324)
 __sys_bind (net/socket.c:1792)
 __arm64_sys_bind (net/socket.c:1801)
 invoke_syscall (arch/arm64/kernel/syscall.c:? arch/arm64/kernel/syscall.c:52)
 el0_svc_common (./include/linux/thread_info.h:127 arch/arm64/kernel/syscall.c:147)
 do_el0_svc (arch/arm64/kernel/syscall.c:189)
 el0_svc (./arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:144 arch/arm64/kernel/entry-common.c:648)
 el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:?)
 el0t_64_sync (arch/arm64/kernel/entry.S:591)

Allocated by task 168:
 kasan_set_track (mm/kasan/common.c:45 mm/kasan/common.c:52)
 kasan_save_alloc_info (mm/kasan/generic.c:512)
 __kasan_kmalloc (mm/kasan/common.c:383)
 __kmalloc (mm/slab_common.c:? mm/slab_common.c:998)
 unix_bind (net/unix/af_unix.c:257 net/unix/af_unix.c:1213 net/unix/af_unix.c:1324)
 __sys_bind (net/socket.c:1792)
 __arm64_sys_bind (net/socket.c:1801)
 invoke_syscall (arch/arm64/kernel/syscall.c:? arch/arm64/kernel/syscall.c:52)
 el0_svc_common (./include/linux/thread_info.h:127 arch/arm64/kernel/syscall.c:147)
 do_el0_svc (arch/arm64/kernel/syscall.c:189)
 el0_svc (./arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:144 arch/arm64/kernel/entry-common.c:648)
 el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:?)
 el0t_64_sync (arch/arm64/kernel/entry.S:591)

The buggy address belongs to the object at ffff000015492700
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes to the right of
 allocated 119-byte region [ffff000015492700, ffff000015492777)

The buggy address belongs to the physical page:
page:00000000aeab52ba refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55492
anon flags: 0x3fffc0000000200(slab|node=0|zone=0|lastcpupid=0xffff)
page_type: 0xffffffff()
raw: 03fffc0000000200 ffff0000084018c0 fffffc00003d0e00 0000000000000005
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000015492600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff000015492680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff000015492700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 07 fc
                                                             ^
 ffff000015492780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff000015492800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 06d4c8a808 ("af_unix: Fix fortify_panic() in unix_bind_bsd().")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/netdev/202307262110.659e5e8-oliver.sang@intel.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230726190828.47874-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-07-27 11:36:55 +02:00
Kuniyuki Iwashima
06d4c8a808 af_unix: Fix fortify_panic() in unix_bind_bsd().
syzkaller found a bug in unix_bind_bsd() [0].  We can reproduce it
by bind()ing a socket on a path with length 108.

108 is the size of sun_addr of struct sockaddr_un and is the maximum
valid length for the pathname socket.  When calling bind(), we use
struct sockaddr_storage as the actual buffer size, so terminating
sun_addr[108] with null is legitimate as done in unix_mkname_bsd().

However, strlen(sunaddr) for such a case causes fortify_panic() if
CONFIG_FORTIFY_SOURCE=y.  __fortify_strlen() has no idea about the
actual buffer size and see the string as unterminated.

Let's use strnlen() to allow sun_addr to be unterminated at 107.

[0]:
detected buffer overflow in __fortify_strlen
kernel BUG at lib/string_helpers.c:1031!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 255 Comm: syz-executor296 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #4
Hardware name: linux,dummy-virt (DT)
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : fortify_panic+0x1c/0x20 lib/string_helpers.c:1030
lr : fortify_panic+0x1c/0x20 lib/string_helpers.c:1030
sp : ffff800089817af0
x29: ffff800089817af0 x28: ffff800089817b40 x27: 1ffff00011302f68
x26: 000000000000006e x25: 0000000000000012 x24: ffff800087e60140
x23: dfff800000000000 x22: ffff800089817c20 x21: ffff800089817c8e
x20: 000000000000006c x19: ffff00000c323900 x18: ffff800086ab1630
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000001
x14: 1ffff00011302eb8 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 64a26b65474d2a00
x8 : 64a26b65474d2a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800089817438 x4 : ffff800086ac99e0 x3 : ffff800080f19e8c
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 000000000000002c
Call trace:
 fortify_panic+0x1c/0x20 lib/string_helpers.c:1030
 _Z16__fortify_strlenPKcU25pass_dynamic_object_size1 include/linux/fortify-string.h:217 [inline]
 unix_bind_bsd net/unix/af_unix.c:1212 [inline]
 unix_bind+0xba8/0xc58 net/unix/af_unix.c:1326
 __sys_bind+0x1ac/0x248 net/socket.c:1792
 __do_sys_bind net/socket.c:1803 [inline]
 __se_sys_bind net/socket.c:1801 [inline]
 __arm64_sys_bind+0x7c/0x94 net/socket.c:1801
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x134/0x240 arch/arm64/kernel/syscall.c:139
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:188
 el0_svc+0x2c/0x7c arch/arm64/kernel/entry-common.c:647
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: aa0003e1 d0000e80 91030000 97ffc91a (d4210000)

Fixes: df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230724213425.22920-2-kuniyu@amazon.com
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-25 20:10:05 -07:00
Alexander Mikhalitsyn
a9c49cc2f5 net: scm: introduce and use scm_recv_unix helper
Recently, our friends from bluetooth subsystem reported [1] that after
commit 5e2ff6704a ("scm: add SO_PASSPIDFD and SCM_PIDFD") scm_recv()
helper become unusable in kernel modules (because it uses unexported
pidfd_prepare() API).

We were aware of this issue and workarounded it in a hard way
by commit 97154bcf4d ("af_unix: Kconfig: make CONFIG_UNIX bool").

But recently a new functionality was added in the scope of commit
817efd3cad74 ("Bluetooth: hci_sock: Forward credentials to monitor")
and after that bluetooth can't be compiled as a kernel module.

After some discussion in [1] we decided to split scm_recv() into
two helpers, one won't support SCM_PIDFD (used for unix sockets),
and another one will be completely the same as it was before commit
5e2ff6704a ("scm: add SO_PASSPIDFD and SCM_PIDFD").

Link: https://lore.kernel.org/lkml/CAJqdLrpFcga4n7wxBhsFqPQiN8PKFVr6U10fKcJ9W7AcZn+o6Q@mail.gmail.com/ [1]
Fixes: 5e2ff6704a ("scm: add SO_PASSPIDFD and SCM_PIDFD")
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230627174314.67688-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-27 10:50:22 -07:00
Kuniyuki Iwashima
9d797ee2dc Revert "af_unix: Call scm_recv() only after scm_set_cred()."
This reverts commit 3f5f118bb6.

Konrad reported that desktop environment below cannot be reached after
commit 3f5f118bb6 ("af_unix: Call scm_recv() only after scm_set_cred().")

  - postmarketOS (Alpine Linux w/ musl 1.2.4)
  - busybox 1.36.1
  - GNOME 44.1
  - networkmanager 1.42.6
  - openrc 0.47

Regarding to the warning of SO_PASSPIDFD, I'll post another patch to
suppress it by skipping SCM_PIDFD if scm->pid == NULL in scm_pidfd_recv().

Reported-by: Konrad Dybcio <konradybcio@kernel.org>
Link: https://lore.kernel.org/netdev/8c7f9abd-4f84-7296-2788-1e130d6304a0@kernel.org/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Gal Pressman <gal@nvidia.com>
Link: https://lore.kernel.org/r/20230626205837.82086-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-27 09:35:53 -07:00
David Howells
dc97391e66 sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)
Remove ->sendpage() and ->sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24 15:50:13 -07:00
Kuniyuki Iwashima
3f5f118bb6 af_unix: Call scm_recv() only after scm_set_cred().
syzkaller hit a WARN_ON_ONCE(!scm->pid) in scm_pidfd_recv().

In unix_stream_read_generic(), if there is no skb in the queue, we could
bail out the do-while loop without calling scm_set_cred():

  1. No skb in the queue
  2. sk is non-blocking
       or
     shutdown(sk, RCV_SHUTDOWN) is called concurrently
       or
     peer calls close()

If the socket is configured with SO_PASSCRED or SO_PASSPIDFD, scm_recv()
would populate cmsg with garbage.

Let's not call scm_recv() unless there is skb to receive.

WARNING: CPU: 1 PID: 3245 at include/net/scm.h:138 scm_pidfd_recv include/net/scm.h:138 [inline]
WARNING: CPU: 1 PID: 3245 at include/net/scm.h:138 scm_recv.constprop.0+0x754/0x850 include/net/scm.h:177
Modules linked in:
CPU: 1 PID: 3245 Comm: syz-executor.1 Not tainted 6.4.0-rc5-01219-gfa0e21fa4443 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:scm_pidfd_recv include/net/scm.h:138 [inline]
RIP: 0010:scm_recv.constprop.0+0x754/0x850 include/net/scm.h:177
Code: 67 fd e9 55 fd ff ff e8 4a 70 67 fd e9 7f fd ff ff e8 40 70 67 fd e9 3e fb ff ff e8 36 70 67 fd e9 02 fd ff ff e8 8c 3a 20 fd <0f> 0b e9 fe fb ff ff e8 50 70 67 fd e9 2e f9 ff ff e8 46 70 67 fd
RSP: 0018:ffffc90009af7660 EFLAGS: 00010216
RAX: 00000000000000a1 RBX: ffff888041e58a80 RCX: ffffc90003852000
RDX: 0000000000040000 RSI: ffffffff842675b4 RDI: 0000000000000007
RBP: ffffc90009af7810 R08: 0000000000000007 R09: 0000000000000013
R10: 00000000000000f8 R11: 0000000000000001 R12: ffffc90009af7db0
R13: 0000000000000000 R14: ffff888041e58a88 R15: 1ffff9200135eecc
FS:  00007f6b7113f640(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b7111de38 CR3: 0000000012a6e002 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
 <TASK>
 unix_stream_read_generic+0x5fe/0x1f50 net/unix/af_unix.c:2830
 unix_stream_recvmsg+0x194/0x1c0 net/unix/af_unix.c:2880
 sock_recvmsg_nosec net/socket.c:1019 [inline]
 sock_recvmsg+0x188/0x1d0 net/socket.c:1040
 ____sys_recvmsg+0x210/0x610 net/socket.c:2712
 ___sys_recvmsg+0xff/0x190 net/socket.c:2754
 do_recvmmsg+0x25d/0x6c0 net/socket.c:2848
 __sys_recvmmsg net/socket.c:2927 [inline]
 __do_sys_recvmmsg net/socket.c:2950 [inline]
 __se_sys_recvmmsg net/socket.c:2943 [inline]
 __x64_sys_recvmmsg+0x224/0x290 net/socket.c:2943
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f6b71da2e5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007f6b7113ecc8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007f6b71da2e5d
RDX: 0000000000000007 RSI: 0000000020006600 RDI: 000000000000000b
RBP: 00000000004bc050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000120 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f6b71e03530 R15: 0000000000000000
 </TASK>

Fixes: 5e2ff6704a ("scm: add SO_PASSPIDFD and SCM_PIDFD")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Alexander Mikhalitsyn <alexander@mihalicyn.com>
Link: https://lore.kernel.org/r/20230622184351.91544-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24 15:15:01 -07:00
Alexander Mikhalitsyn
97154bcf4d af_unix: Kconfig: make CONFIG_UNIX bool
Let's make CONFIG_UNIX a bool instead of a tristate.
We've decided to do that during discussion about SCM_PIDFD patchset [1].

[1] https://lore.kernel.org/lkml/20230524081933.44dc8bea@kernel.org/

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-12 10:45:50 +01:00
Alexander Mikhalitsyn
7b26952a91 net: core: add getsockopt SO_PEERPIDFD
Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd.
This thing is direct analog of SO_PEERCRED which allows to get plain PID.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: bpf@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-12 10:45:50 +01:00
Alexander Mikhalitsyn
5e2ff6704a scm: add SO_PASSPIDFD and SCM_PIDFD
Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS,
but it contains pidfd instead of plain pid, which allows programmers not
to care about PID reuse problem.

We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because
it depends on a pidfd_prepare() API which is not exported to the kernel
modules.

Idea comes from UAPI kernel group:
https://uapi-group.org/kernel-features/

Big thanks to Christian Brauner and Lennart Poettering for productive
discussions about this.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Tested-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-12 10:45:49 +01:00
Jakub Kicinski
d4031ec844 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/raw.c
  3632679d9e ("ipv{4,6}/raw: fix output xfrm lookup wrt protocol")
  c85be08fc4 ("raw: Stop using RTO_ONLINK.")
https://lore.kernel.org/all/20230525110037.2b532b83@canb.auug.org.au/

Adjacent changes:

drivers/net/ethernet/freescale/fec_main.c
  9025944fdd ("net: fec: add dma_wmb to ensure correct descriptor values")
  144470c88c ("net: fec: using the standard return codes when xdp xmit errors")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-25 19:57:39 -07:00
David Howells
57d44a354a unix: Convert unix_stream_sendpage() to use MSG_SPLICE_PAGES
Convert unix_stream_sendpage() to use sendmsg() with MSG_SPLICE_PAGES
rather than directly splicing in the pages itself.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Kuniyuki Iwashima <kuniyu@amazon.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23 20:48:28 -07:00
David Howells
a0dbf5f818 af_unix: Support MSG_SPLICE_PAGES
Make AF_UNIX sendmsg() support MSG_SPLICE_PAGES, splicing in pages from the
source iterator if possible and copying the data in otherwise.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Kuniyuki Iwashima <kuniyu@amazon.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23 20:48:27 -07:00
David Howells
96449f9024 net: Pass max frags into skb_append_pagefrags()
Pass the maximum number of fragments into skb_append_pagefrags() rather
than using MAX_SKB_FRAGS so that it can be used from code that wants to
specify sysctl_max_skb_frags.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Ahern <dsahern@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23 20:48:27 -07:00
John Fastabend
78fa0d61d9 bpf, sockmap: Pass skb ownership through read_skb
The read_skb hook calls consume_skb() now, but this means that if the
recv_actor program wants to use the skb it needs to inc the ref cnt
so that the consume_skb() doesn't kfree the sk_buff.

This is problematic because in some error cases under memory pressure
we may need to linearize the sk_buff from sk_psock_skb_ingress_enqueue().
Then we get this,

 skb_linearize()
   __pskb_pull_tail()
     pskb_expand_head()
       BUG_ON(skb_shared(skb))

Because we incremented users refcnt from sk_psock_verdict_recv() we
hit the bug on with refcnt > 1 and trip it.

To fix lets simply pass ownership of the sk_buff through the skb_read
call. Then we can drop the consume from read_skb handlers and assume
the verdict recv does any required kfree.

Bug found while testing in our CI which runs in VMs that hit memory
constraints rather regularly. William tested TCP read_skb handlers.

[  106.536188] ------------[ cut here ]------------
[  106.536197] kernel BUG at net/core/skbuff.c:1693!
[  106.536479] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[  106.536726] CPU: 3 PID: 1495 Comm: curl Not tainted 5.19.0-rc5 #1
[  106.537023] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.16.0-1 04/01/2014
[  106.537467] RIP: 0010:pskb_expand_head+0x269/0x330
[  106.538585] RSP: 0018:ffffc90000138b68 EFLAGS: 00010202
[  106.538839] RAX: 000000000000003f RBX: ffff8881048940e8 RCX: 0000000000000a20
[  106.539186] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff8881048940e8
[  106.539529] RBP: ffffc90000138be8 R08: 00000000e161fd1a R09: 0000000000000000
[  106.539877] R10: 0000000000000018 R11: 0000000000000000 R12: ffff8881048940e8
[  106.540222] R13: 0000000000000003 R14: 0000000000000000 R15: ffff8881048940e8
[  106.540568] FS:  00007f277dde9f00(0000) GS:ffff88813bd80000(0000) knlGS:0000000000000000
[  106.540954] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  106.541227] CR2: 00007f277eeede64 CR3: 000000000ad3e000 CR4: 00000000000006e0
[  106.541569] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  106.541915] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  106.542255] Call Trace:
[  106.542383]  <IRQ>
[  106.542487]  __pskb_pull_tail+0x4b/0x3e0
[  106.542681]  skb_ensure_writable+0x85/0xa0
[  106.542882]  sk_skb_pull_data+0x18/0x20
[  106.543084]  bpf_prog_b517a65a242018b0_bpf_skskb_http_verdict+0x3a9/0x4aa9
[  106.543536]  ? migrate_disable+0x66/0x80
[  106.543871]  sk_psock_verdict_recv+0xe2/0x310
[  106.544258]  ? sk_psock_write_space+0x1f0/0x1f0
[  106.544561]  tcp_read_skb+0x7b/0x120
[  106.544740]  tcp_data_queue+0x904/0xee0
[  106.544931]  tcp_rcv_established+0x212/0x7c0
[  106.545142]  tcp_v4_do_rcv+0x174/0x2a0
[  106.545326]  tcp_v4_rcv+0xe70/0xf60
[  106.545500]  ip_protocol_deliver_rcu+0x48/0x290
[  106.545744]  ip_local_deliver_finish+0xa7/0x150

Fixes: 04919bed94 ("tcp: Introduce tcp_read_skb()")
Reported-by: William Findlay <will@isovalent.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: William Findlay <will@isovalent.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-2-john.fastabend@gmail.com
2023-05-23 16:09:47 +02:00
Kuniyuki Iwashima
e1d09c2c2f af_unix: Fix data races around sk->sk_shutdown.
KCSAN found a data race around sk->sk_shutdown where unix_release_sock()
and unix_shutdown() update it under unix_state_lock(), OTOH unix_poll()
and unix_dgram_poll() read it locklessly.

We need to annotate the writes and reads with WRITE_ONCE() and READ_ONCE().

BUG: KCSAN: data-race in unix_poll / unix_release_sock

write to 0xffff88800d0f8aec of 1 bytes by task 264 on cpu 0:
 unix_release_sock+0x75c/0x910 net/unix/af_unix.c:631
 unix_release+0x59/0x80 net/unix/af_unix.c:1042
 __sock_release+0x7d/0x170 net/socket.c:653
 sock_close+0x19/0x30 net/socket.c:1397
 __fput+0x179/0x5e0 fs/file_table.c:321
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x116/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297
 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffff88800d0f8aec of 1 bytes by task 222 on cpu 1:
 unix_poll+0xa3/0x2a0 net/unix/af_unix.c:3170
 sock_poll+0xcf/0x2b0 net/socket.c:1385
 vfs_poll include/linux/poll.h:88 [inline]
 ep_item_poll.isra.0+0x78/0xc0 fs/eventpoll.c:855
 ep_send_events fs/eventpoll.c:1694 [inline]
 ep_poll fs/eventpoll.c:1823 [inline]
 do_epoll_wait+0x6c4/0xea0 fs/eventpoll.c:2258
 __do_sys_epoll_wait fs/eventpoll.c:2270 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2265 [inline]
 __x64_sys_epoll_wait+0xcc/0x190 fs/eventpoll.c:2265
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x00 -> 0x03

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 222 Comm: dbus-broker Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 3c73419c09 ("af_unix: fix 'poll for write'/ connected DGRAM sockets")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10 19:06:53 -07:00
Kuniyuki Iwashima
679ed006d4 af_unix: Fix a data race of sk->sk_receive_queue->qlen.
KCSAN found a data race of sk->sk_receive_queue->qlen where recvmsg()
updates qlen under the queue lock and sendmsg() checks qlen under
unix_state_sock(), not the queue lock, so the reader side needs
READ_ONCE().

BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_wait_for_peer

write (marked) to 0xffff888019fe7c68 of 4 bytes by task 49792 on cpu 0:
 __skb_unlink include/linux/skbuff.h:2347 [inline]
 __skb_try_recv_from_queue+0x3de/0x470 net/core/datagram.c:197
 __skb_try_recv_datagram+0xf7/0x390 net/core/datagram.c:263
 __unix_dgram_recvmsg+0x109/0x8a0 net/unix/af_unix.c:2452
 unix_dgram_recvmsg+0x94/0xa0 net/unix/af_unix.c:2549
 sock_recvmsg_nosec net/socket.c:1019 [inline]
 ____sys_recvmsg+0x3a3/0x3b0 net/socket.c:2720
 ___sys_recvmsg+0xc8/0x150 net/socket.c:2764
 do_recvmmsg+0x182/0x560 net/socket.c:2858
 __sys_recvmmsg net/socket.c:2937 [inline]
 __do_sys_recvmmsg net/socket.c:2960 [inline]
 __se_sys_recvmmsg net/socket.c:2953 [inline]
 __x64_sys_recvmmsg+0x153/0x170 net/socket.c:2953
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffff888019fe7c68 of 4 bytes by task 49793 on cpu 1:
 skb_queue_len include/linux/skbuff.h:2127 [inline]
 unix_recvq_full net/unix/af_unix.c:229 [inline]
 unix_wait_for_peer+0x154/0x1a0 net/unix/af_unix.c:1445
 unix_dgram_sendmsg+0x13bc/0x14b0 net/unix/af_unix.c:2048
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x148/0x160 net/socket.c:747
 ____sys_sendmsg+0x20e/0x620 net/socket.c:2503
 ___sys_sendmsg+0xc6/0x140 net/socket.c:2557
 __sys_sendmmsg+0x11d/0x370 net/socket.c:2643
 __do_sys_sendmmsg net/socket.c:2672 [inline]
 __se_sys_sendmmsg net/socket.c:2669 [inline]
 __x64_sys_sendmmsg+0x58/0x70 net/socket.c:2669
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x0000000b -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 49793 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10 19:06:53 -07:00
Eric Dumazet
cc04410af7 af_unix: annotate lockless accesses to sk->sk_err
unix_poll() and unix_dgram_poll() read sk->sk_err
without any lock held.

Add relevant READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-17 08:25:05 +00:00
Jakub Kicinski
d0ddf5065f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Documentation/bpf/bpf_devel_QA.rst
  b7abcd9c65 ("bpf, doc: Link to submitting-patches.rst for general patch submission info")
  d56b0c461d ("bpf, docs: Fix link to netdev-FAQ target")
https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-09 22:22:11 -08:00
Eric Dumazet
2aab4b9690 af_unix: fix struct pid leaks in OOB support
syzbot reported struct pid leak [1].

Issue is that queue_oob() calls maybe_add_creds() which potentially
holds a reference on a pid.

But skb->destructor is not set (either directly or by calling
unix_scm_to_skb())

This means that subsequent kfree_skb() or consume_skb() would leak
this reference.

In this fix, I chose to fully support scm even for the OOB message.

[1]
BUG: memory leak
unreferenced object 0xffff8881053e7f80 (size 128):
comm "syz-executor242", pid 5066, jiffies 4294946079 (age 13.220s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff812ae26a>] alloc_pid+0x6a/0x560 kernel/pid.c:180
[<ffffffff812718df>] copy_process+0x169f/0x26c0 kernel/fork.c:2285
[<ffffffff81272b37>] kernel_clone+0xf7/0x610 kernel/fork.c:2684
[<ffffffff812730cc>] __do_sys_clone+0x7c/0xb0 kernel/fork.c:2825
[<ffffffff849ad699>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff849ad699>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
[<ffffffff84a0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 314001f0bf ("af_unix: Add OOB support")
Reported-by: syzbot+7699d9e5635c10253a27@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Rao Shoaib <rao.shoaib@oracle.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230307164530.771896-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-08 23:26:03 -08:00
Eric Dumazet
1036908045 net: reclaim skb->scm_io_uring bit
Commit 0091bfc817 ("io_uring/af_unix: defer registered
files gc to io_uring release") added one bit to struct sk_buff.

This structure is critical for networking, and we try very hard
to not add bloat on it, unless absolutely required.

For instance, we can use a specific destructor as a wrapper
around unix_destruct_scm(), to identify skbs that unix_gc()
has to special case.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-08 13:21:47 +00:00
Liu Jian
d900f3d20c bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser()
When the buffer length of the recvmsg system call is 0, we got the
flollowing soft lockup problem:

watchdog: BUG: soft lockup - CPU#3 stuck for 27s! [a.out:6149]
CPU: 3 PID: 6149 Comm: a.out Kdump: loaded Not tainted 6.2.0+ #30
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:remove_wait_queue+0xb/0xc0
Code: 5e 41 5f c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 57 <41> 56 41 55 41 54 55 48 89 fd 53 48 89 f3 4c 8d 6b 18 4c 8d 73 20
RSP: 0018:ffff88811b5978b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88811a7d3780 RCX: ffffffffb7a4d768
RDX: dffffc0000000000 RSI: ffff88811b597908 RDI: ffff888115408040
RBP: 1ffff110236b2f1b R08: 0000000000000000 R09: ffff88811a7d37e7
R10: ffffed10234fa6fc R11: 0000000000000001 R12: ffff88811179b800
R13: 0000000000000001 R14: ffff88811a7d38a8 R15: ffff88811a7d37e0
FS:  00007f6fb5398740(0000) GS:ffff888237180000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000010b6ba002 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tcp_msg_wait_data+0x279/0x2f0
 tcp_bpf_recvmsg_parser+0x3c6/0x490
 inet_recvmsg+0x280/0x290
 sock_recvmsg+0xfc/0x120
 ____sys_recvmsg+0x160/0x3d0
 ___sys_recvmsg+0xf0/0x180
 __sys_recvmsg+0xea/0x1a0
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

The logic in tcp_bpf_recvmsg_parser is as follows:

msg_bytes_ready:
	copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
	if (!copied) {
		wait data;
		goto msg_bytes_ready;
	}

In this case, "copied" always is 0, the infinite loop occurs.

According to the Linux system call man page, 0 should be returned in this
case. Therefore, in tcp_bpf_recvmsg_parser(), if the length is 0, directly
return. Also modify several other functions with the same problem.

Fixes: 1f5be6b3b0 ("udp: Implement udp_bpf_recvmsg() for sockmap")
Fixes: 9825d866ce ("af_unix: Implement unix_dgram_bpf_recvmsg()")
Fixes: c5d2177a72 ("bpf, sockmap: Fix race in ingress receive verdict with redirect to self")
Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230303080946.1146638-1-liujian56@huawei.com
2023-03-03 17:25:15 +01:00
Linus Torvalds
5b7c4cabbb Networking changes for 6.3.
Core
 ----
 
  - Add dedicated kmem_cache for typical/small skb->head, avoid having
    to access struct page at kfree time, and improve memory use.
 
  - Introduce sysctl to set default RPS configuration for new netdevs.
 
  - Define Netlink protocol specification format which can be used
    to describe messages used by each family and auto-generate parsers.
    Add tools for generating kernel data structures and uAPI headers.
 
  - Expose all net/core sysctls inside netns.
 
  - Remove 4s sleep in netpoll if carrier is instantly detected on boot.
 
  - Add configurable limit of MDB entries per port, and port-vlan.
 
  - Continue populating drop reasons throughout the stack.
 
  - Retire a handful of legacy Qdiscs and classifiers.
 
 Protocols
 ---------
 
  - Support IPv4 big TCP (TSO frames larger than 64kB).
 
  - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
    on socket by socket basis.
 
  - Track and report in procfs number of MPTCP sockets used.
 
  - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP
    path manager.
 
  - IPv6: don't check net.ipv6.route.max_size and rely on garbage
    collection to free memory (similarly to IPv4).
 
  - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
 
  - ICMP: add per-rate limit counters.
 
  - Add support for user scanning requests in ieee802154.
 
  - Remove static WEP support.
 
  - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
    reporting.
 
  - WiFi 7 EHT channel puncturing support (client & AP).
 
 BPF
 ---
 
  - Add a rbtree data structure following the "next-gen data structure"
    precedent set by recently added linked list, that is, by using
    kfunc + kptr instead of adding a new BPF map type.
 
  - Expose XDP hints via kfuncs with initial support for RX hash and
    timestamp metadata.
 
  - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key
    to better support decap on GRE tunnel devices not operating
    in collect metadata.
 
  - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
 
  - Remove the need for trace_printk_lock for bpf_trace_printk
    and bpf_trace_vprintk helpers.
 
  - Extend libbpf's bpf_tracing.h support for tracing arguments of
    kprobes/uprobes and syscall as a special case.
 
  - Significantly reduce the search time for module symbols
    by livepatch and BPF.
 
  - Enable cpumasks to be used as kptrs, which is useful for tracing
    programs tracking which tasks end up running on which CPUs in
    different time intervals.
 
  - Add support for BPF trampoline on s390x and riscv64.
 
  - Add capability to export the XDP features supported by the NIC.
 
  - Add __bpf_kfunc tag for marking kernel functions as kfuncs.
 
  - Add cgroup.memory=nobpf kernel parameter option to disable BPF
    memory accounting for container environments.
 
 Netfilter
 ---------
 
  - Remove the CLUSTERIP target. It has been marked as obsolete
    for years, and we still have WARN splats wrt. races of
    the out-of-band /proc interface installed by this target.
 
  - Add 'destroy' commands to nf_tables. They are identical to
    the existing 'delete' commands, but do not return an error if
    the referenced object (set, chain, rule...) did not exist.
 
 Driver API
 ----------
 
  - Improve cpumask_local_spread() locality to help NICs set the right
    IRQ affinity on AMD platforms.
 
  - Separate C22 and C45 MDIO bus transactions more clearly.
 
  - Introduce new DCB table to control DSCP rewrite on egress.
 
  - Support configuration of Physical Layer Collision Avoidance (PLCA)
    Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
    shared medium Ethernet.
 
  - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
    preemption of low priority frames by high priority frames.
 
  - Add support for controlling MACSec offload using netlink SET.
 
  - Rework devlink instance refcounts to allow registration and
    de-registration under the instance lock. Split the code into multiple
    files, drop some of the unnecessarily granular locks and factor out
    common parts of netlink operation handling.
 
  - Add TX frame aggregation parameters (for USB drivers).
 
  - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
    messages with notifications for debug.
 
  - Allow offloading of UDP NEW connections via act_ct.
 
  - Add support for per action HW stats in TC.
 
  - Support hardware miss to TC action (continue processing in SW from
    a specific point in the action chain).
 
  - Warn if old Wireless Extension user space interface is used with
    modern cfg80211/mac80211 drivers. Do not support Wireless Extensions
    for Wi-Fi 7 devices at all. Everyone should switch to using nl80211
    interface instead.
 
  - Improve the CAN bit timing configuration. Use extack to return error
    messages directly to user space, update the SJW handling, including
    the definition of a new default value that will benefit CAN-FD
    controllers, by increasing their oscillator tolerance.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - nVidia BlueField-3 support (control traffic driver)
    - Ethernet support for imx93 SoCs
    - Motorcomm yt8531 gigabit Ethernet PHY
    - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
    - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
    - Amlogic gxl MDIO mux
 
  - WiFi:
    - RealTek RTL8188EU (rtl8xxxu)
    - Qualcomm Wi-Fi 7 devices (ath12k)
 
  - CAN:
    - Renesas R-Car V4H
 
 Drivers
 -------
 
  - Bluetooth:
    - Set Per Platform Antenna Gain (PPAG) for Intel controllers.
 
  - Ethernet NICs:
    - Intel (1G, igc):
      - support TSN / Qbv / packet scheduling features of i226 model
    - Intel (100G, ice):
      - use GNSS subsystem instead of TTY
      - multi-buffer XDP support
      - extend support for GPIO pins to E823 devices
    - nVidia/Mellanox:
      - update the shared buffer configuration on PFC commands
      - implement PTP adjphase function for HW offset control
      - TC support for Geneve and GRE with VF tunnel offload
      - more efficient crypto key management method
      - multi-port eswitch support
    - Netronome/Corigine:
      - add DCB IEEE support
      - support IPsec offloading for NFP3800
    - Freescale/NXP (enetc):
      - enetc: support XDP_REDIRECT for XDP non-linear buffers
      - enetc: improve reconfig, avoid link flap and waiting for idle
      - enetc: support MAC Merge layer
    - Other NICs:
      - sfc/ef100: add basic devlink support for ef100
      - ionic: rx_push mode operation (writing descriptors via MMIO)
      - bnxt: use the auxiliary bus abstraction for RDMA
      - r8169: disable ASPM and reset bus in case of tx timeout
      - cpsw: support QSGMII mode for J721e CPSW9G
      - cpts: support pulse-per-second output
      - ngbe: add an mdio bus driver
      - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
      - r8152: handle devices with FW with NCM support
      - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
      - virtio-net: support multi buffer XDP
      - virtio/vsock: replace virtio_vsock_pkt with sk_buff
      - tsnep: XDP support
 
  - Ethernet high-speed switches:
    - nVidia/Mellanox (mlxsw):
      - add support for latency TLV (in FW control messages)
    - Microchip (sparx5):
      - separate explicit and implicit traffic forwarding rules, make
        the implicit rules always active
      - add support for egress DSCP rewrite
      - IS0 VCAP support (Ingress Classification)
      - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.)
      - ES2 VCAP support (Egress Access Control)
      - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1)
 
  - Ethernet embedded switches:
    - Marvell (mv88e6xxx):
      - add MAB (port auth) offload support
      - enable PTP receive for mv88e6390
    - NXP (ocelot):
      - support MAC Merge layer
      - support for the the vsc7512 internal copper phys
    - Microchip:
      - lan9303: convert to PHYLINK
      - lan966x: support TC flower filter statistics
      - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
      - lan937x: support Credit Based Shaper configuration
      - ksz9477: support Energy Efficient Ethernet
    - other:
      - qca8k: convert to regmap read/write API, use bulk operations
      - rswitch: Improve TX timestamp accuracy
 
  - Intel WiFi (iwlwifi):
    - EHT (Wi-Fi 7) rate reporting
    - STEP equalizer support: transfer some STEP (connection to radio
      on platforms with integrated wifi) related parameters from the
      BIOS to the firmware.
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - IPQ5018 support
    - Fine Timing Measurement (FTM) responder role support
    - channel 177 support
 
  - MediaTek WiFi (mt76):
    - per-PHY LED support
    - mt7996: EHT (Wi-Fi 7) support
    - Wireless Ethernet Dispatch (WED) reset support
    - switch to using page pool allocator
 
  - RealTek WiFi (rtw89):
    - support new version of Bluetooth co-existance
 
  - Mobile:
    - rmnet: support TX aggregation.
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...
2023-02-21 18:24:12 -08:00
Jakub Kicinski
509f15b9c5 net: add missing includes of linux/splice.h
Number of files depend on linux/splice.h getting included
by linux/skbuff.h which soon will no longer be the case.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-27 11:19:46 +00:00
Christian Brauner
abf08576af
fs: port vfs_*() helpers to struct mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-18 17:51:45 +01:00
Kirill Tkhai
b27401a30e unix: Improve locking scheme in unix_show_fdinfo()
After switching to TCP_ESTABLISHED or TCP_LISTEN sk_state, alive SOCK_STREAM
and SOCK_SEQPACKET sockets can't change it anymore (since commit 3ff8bff704
"unix: Fix race in SOCK_SEQPACKET's unix_dgram_sendmsg()").

Thus, we do not need to take lock here.

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-16 11:21:11 +00:00
Kirill Tkhai
3ff8bff704 unix: Fix race in SOCK_SEQPACKET's unix_dgram_sendmsg()
There is a race resulting in alive SOCK_SEQPACKET socket
may change its state from TCP_ESTABLISHED to TCP_CLOSE:

unix_release_sock(peer)                  unix_dgram_sendmsg(sk)
  sock_orphan(peer)
    sock_set_flag(peer, SOCK_DEAD)
                                           sock_alloc_send_pskb()
                                             if !(sk->sk_shutdown & SEND_SHUTDOWN)
                                               OK
                                           if sock_flag(peer, SOCK_DEAD)
                                             sk->sk_state = TCP_CLOSE
  sk->sk_shutdown = SHUTDOWN_MASK

After that socket sk remains almost normal: it is able to connect, listen, accept
and recvmsg, while it can't sendmsg.

Since this is the only possibility for alive SOCK_SEQPACKET to change
the state in such way, we should better fix this strange and potentially
danger corner case.

Note, that we will return EPIPE here like this is normally done in sock_alloc_send_pskb().
Originally used ECONNREFUSED looks strange, since it's strange to return
a specific retval in dependence of race in kernel, when user can't affect on this.

Also, move TCP_CLOSE assignment for SOCK_DGRAM sockets under state lock
to fix race with unix_dgram_connect():

unix_dgram_connect(other)            unix_dgram_sendmsg(sk)
                                       unix_peer(sk) = NULL
                                       unix_state_unlock(sk)
  unix_state_double_lock(sk, other)
  sk->sk_state  = TCP_ESTABLISHED
  unix_peer(sk) = other
  unix_state_double_unlock(sk, other)
                                       sk->sk_state  = TCP_CLOSED

This patch fixes both of these races.

Fixes: 83301b5367 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
Link: https://lore.kernel.org/r/135fda25-22d5-837a-782b-ceee50e19844@ya.ru
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-12-15 11:35:18 +01:00
Yang Yingliang
73e341e028 af_unix: call proto_unregister() in the error path in af_unix_init()
If register unix_stream_proto returns error, unix_dgram_proto needs
be unregistered.

Fixes: 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-12 10:04:08 +00:00
Kuniyuki Iwashima
b3abe42e94 af_unix: Get user_ns from in_skb in unix_diag_get_exact().
Wei Chen reported a NULL deref in sk_user_ns() [0][1], and Paolo diagnosed
the root cause: in unix_diag_get_exact(), the newly allocated skb does not
have sk. [2]

We must get the user_ns from the NETLINK_CB(in_skb).sk and pass it to
sk_diag_fill().

[0]:
BUG: kernel NULL pointer dereference, address: 0000000000000270
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 12bbce067 P4D 12bbce067 PUD 12bc40067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 27942 Comm: syz-executor.0 Not tainted 6.1.0-rc5-next-20221118 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
RIP: 0010:sk_user_ns include/net/sock.h:920 [inline]
RIP: 0010:sk_diag_dump_uid net/unix/diag.c:119 [inline]
RIP: 0010:sk_diag_fill+0x77d/0x890 net/unix/diag.c:170
Code: 89 ef e8 66 d4 2d fd c7 44 24 40 00 00 00 00 49 8d 7c 24 18 e8
54 d7 2d fd 49 8b 5c 24 18 48 8d bb 70 02 00 00 e8 43 d7 2d fd <48> 8b
9b 70 02 00 00 48 8d 7b 10 e8 33 d7 2d fd 48 8b 5b 10 48 8d
RSP: 0018:ffffc90000d67968 EFLAGS: 00010246
RAX: ffff88812badaa48 RBX: 0000000000000000 RCX: ffffffff840d481d
RDX: 0000000000000465 RSI: 0000000000000000 RDI: 0000000000000270
RBP: ffffc90000d679a8 R08: 0000000000000277 R09: 0000000000000000
R10: 0001ffffffffffff R11: 0001c90000d679a8 R12: ffff88812ac03800
R13: ffff88812c87c400 R14: ffff88812ae42210 R15: ffff888103026940
FS:  00007f08b4e6f700(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000270 CR3: 000000012c58b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unix_diag_get_exact net/unix/diag.c:285 [inline]
 unix_diag_handler_dump+0x3f9/0x500 net/unix/diag.c:317
 __sock_diag_cmd net/core/sock_diag.c:235 [inline]
 sock_diag_rcv_msg+0x237/0x250 net/core/sock_diag.c:266
 netlink_rcv_skb+0x13e/0x250 net/netlink/af_netlink.c:2564
 sock_diag_rcv+0x24/0x40 net/core/sock_diag.c:277
 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
 netlink_unicast+0x5e9/0x6b0 net/netlink/af_netlink.c:1356
 netlink_sendmsg+0x739/0x860 net/netlink/af_netlink.c:1932
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2476
 ___sys_sendmsg net/socket.c:2530 [inline]
 __sys_sendmsg+0x197/0x230 net/socket.c:2559
 __do_sys_sendmsg net/socket.c:2568 [inline]
 __se_sys_sendmsg net/socket.c:2566 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2566
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x4697f9
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48
89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f08b4e6ec48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000077bf80 RCX: 00000000004697f9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00000000004d29e9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000077bf80
R13: 0000000000000000 R14: 000000000077bf80 R15: 00007ffdb36bc6c0
 </TASK>
Modules linked in:
CR2: 0000000000000270

[1]: https://lore.kernel.org/netdev/CAO4mrfdvyjFpokhNsiwZiP-wpdSD0AStcJwfKcKQdAALQ9_2Qw@mail.gmail.com/
[2]: https://lore.kernel.org/netdev/e04315e7c90d9a75613f3993c2baf2d344eef7eb.camel@redhat.com/

Fixes: cae9910e73 ("net: Add UNIX_DIAG_UID to Netlink UNIX socket diagnostics.")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Wei Chen <harperchen1110@gmail.com>
Diagnosed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-12-01 10:32:20 +01:00
Pavel Begunkov
fee9ac0664 net: remove SOCK_SUPPORT_ZC from sockmap
sockmap replaces ->sk_prot with its own callbacks, we should remove
SOCK_SUPPORT_ZC as the new proto doesn't support msghdr::ubuf_info.

Cc: <stable@vger.kernel.org> # 6.0
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: e993ffe3da ("net: flag sockets supporting msghdr originated zerocopy")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-28 20:21:25 -07:00
Linus Torvalds
f1947d7c8a Random number generator fixes for Linux 6.1-rc1.
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Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull more random number generator updates from Jason Donenfeld:
 "This time with some large scale treewide cleanups.

  The intent of this pull is to clean up the way callers fetch random
  integers. The current rules for doing this right are:

   - If you want a secure or an insecure random u64, use get_random_u64()

   - If you want a secure or an insecure random u32, use get_random_u32()

     The old function prandom_u32() has been deprecated for a while
     now and is just a wrapper around get_random_u32(). Same for
     get_random_int().

   - If you want a secure or an insecure random u16, use get_random_u16()

   - If you want a secure or an insecure random u8, use get_random_u8()

   - If you want secure or insecure random bytes, use get_random_bytes().

     The old function prandom_bytes() has been deprecated for a while
     now and has long been a wrapper around get_random_bytes()

   - If you want a non-uniform random u32, u16, or u8 bounded by a
     certain open interval maximum, use prandom_u32_max()

     I say "non-uniform", because it doesn't do any rejection sampling
     or divisions. Hence, it stays within the prandom_*() namespace, not
     the get_random_*() namespace.

     I'm currently investigating a "uniform" function for 6.2. We'll see
     what comes of that.

  By applying these rules uniformly, we get several benefits:

   - By using prandom_u32_max() with an upper-bound that the compiler
     can prove at compile-time is ≤65536 or ≤256, internally
     get_random_u16() or get_random_u8() is used, which wastes fewer
     batched random bytes, and hence has higher throughput.

   - By using prandom_u32_max() instead of %, when the upper-bound is
     not a constant, division is still avoided, because
     prandom_u32_max() uses a faster multiplication-based trick instead.

   - By using get_random_u16() or get_random_u8() in cases where the
     return value is intended to indeed be a u16 or a u8, we waste fewer
     batched random bytes, and hence have higher throughput.

  This series was originally done by hand while I was on an airplane
  without Internet. Later, Kees and I worked on retroactively figuring
  out what could be done with Coccinelle and what had to be done
  manually, and then we split things up based on that.

  So while this touches a lot of files, the actual amount of code that's
  hand fiddled is comfortably small"

* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  prandom: remove unused functions
  treewide: use get_random_bytes() when possible
  treewide: use get_random_u32() when possible
  treewide: use get_random_{u8,u16}() when possible, part 2
  treewide: use get_random_{u8,u16}() when possible, part 1
  treewide: use prandom_u32_max() when possible, part 2
  treewide: use prandom_u32_max() when possible, part 1
2022-10-16 15:27:07 -07:00
Linus Torvalds
c98c70ed43 io_uring-6.1-2022-10-13
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Merge tag 'io_uring-6.1-2022-10-13' of git://git.kernel.dk/linux

Pull more io_uring updates from Jens Axboe:
 "A collection of fixes that ended up either being later than the
  initial pull, or dependent on multiple branches (6.0-late being one of
  them) and hence deferred purposely. This contains:

   - Cleanup fixes for the single submitter late 6.0 change, which we
     pushed to 6.1 to keep the 6.0 changes small (Dylan, Pavel)

   - Fix for IORING_OP_CONNECT not handling -EINPROGRESS correctly (me)

   - Ensure that the zc sendmsg variant gets audited correctly (me)

   - Regression fix from this merge window where kiocb_end_write()
     doesn't always gets called, which can cause issues with fs freezing
     (me)

   - Registered files SCM handling fix (Pavel)

   - Regression fix for big sqe dumping in fdinfo (Pavel)

   - Registered buffers accounting fix (Pavel)

   - Remove leftover notification structures, we killed them off late in
     6.0 (Pavel)

   - Minor optimizations (Pavel)

   - Cosmetic variable shadowing fix (Stefan)"

* tag 'io_uring-6.1-2022-10-13' of git://git.kernel.dk/linux:
  io_uring/rw: ensure kiocb_end_write() is always called
  io_uring: fix fdinfo sqe offsets calculation
  io_uring: local variable rw shadows outer variable in io_write
  io_uring/opdef: remove 'audit_skip' from SENDMSG_ZC
  io_uring: optimise locking for local tw with submit_wait
  io_uring: remove redundant memory barrier in io_req_local_work_add
  io_uring/net: handle -EINPROGRESS correct for IORING_OP_CONNECT
  io_uring: remove notif leftovers
  io_uring: correct pinned_vm accounting
  io_uring/af_unix: defer registered files gc to io_uring release
  io_uring: limit registration w/ SINGLE_ISSUER
  io_uring: remove io_register_submitter
  io_uring: simplify __io_uring_add_tctx_node
2022-10-13 21:15:30 -07:00
Pavel Begunkov
0091bfc817 io_uring/af_unix: defer registered files gc to io_uring release
Instead of putting io_uring's registered files in unix_gc() we want it
to be done by io_uring itself. The trick here is to consider io_uring
registered files for cycle detection but not actually putting them down.
Because io_uring can't register other ring instances, this will remove
all refs to the ring file triggering the ->release path and clean up
with io_ring_ctx_free().

Cc: stable@vger.kernel.org
Fixes: 6b06314c47 ("io_uring: add file set registration")
Reported-and-tested-by: David Bouman <dbouman03@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[axboe: add kerneldoc comment to skb, fold in skb leak fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-12 16:30:34 -06:00
Jason A. Donenfeld
a251c17aa5 treewide: use get_random_u32() when possible
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:58 -06:00
Linus Torvalds
30c999937f Scheduler changes for v6.1:
- Debuggability:
 
      - Change most occurances of BUG_ON() to WARN_ON_ONCE()
 
      - Reorganize & fix TASK_ state comparisons, turn it into a bitmap
 
      - Update/fix misc scheduler debugging facilities
 
  - Load-balancing & regular scheduling:
 
      - Improve the behavior of the scheduler in presence of lot of
        SCHED_IDLE tasks - in particular they should not impact other
        scheduling classes.
 
      - Optimize task load tracking, cleanups & fixes
 
      - Clean up & simplify misc load-balancing code
 
  - Freezer:
 
      - Rewrite the core freezer to behave better wrt thawing and be simpler
        in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
        all the fallout.
 
  - Deadline scheduler:
 
      - Fix the DL capacity-aware code
 
      - Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
 
      - Relax/optimize locking in task_non_contending()
 
  - Cleanups:
 
      - Factor out the update_current_exec_runtime() helper
 
      - Various cleanups, simplifications
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Debuggability:

   - Change most occurances of BUG_ON() to WARN_ON_ONCE()

   - Reorganize & fix TASK_ state comparisons, turn it into a bitmap

   - Update/fix misc scheduler debugging facilities

  Load-balancing & regular scheduling:

   - Improve the behavior of the scheduler in presence of lot of
     SCHED_IDLE tasks - in particular they should not impact other
     scheduling classes.

   - Optimize task load tracking, cleanups & fixes

   - Clean up & simplify misc load-balancing code

  Freezer:

   - Rewrite the core freezer to behave better wrt thawing and be
     simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
     fixing/adjusting all the fallout.

  Deadline scheduler:

   - Fix the DL capacity-aware code

   - Factor out dl_task_is_earliest_deadline() &
     replenish_dl_new_period()

   - Relax/optimize locking in task_non_contending()

  Cleanups:

   - Factor out the update_current_exec_runtime() helper

   - Various cleanups, simplifications"

* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  sched: Fix more TASK_state comparisons
  sched: Fix TASK_state comparisons
  sched/fair: Move call to list_last_entry() in detach_tasks
  sched/fair: Cleanup loop_max and loop_break
  sched/fair: Make sure to try to detach at least one movable task
  sched: Show PF_flag holes
  freezer,sched: Rewrite core freezer logic
  sched: Widen TAKS_state literals
  sched/wait: Add wait_event_state()
  sched/completion: Add wait_for_completion_state()
  sched: Add TASK_ANY for wait_task_inactive()
  sched: Change wait_task_inactive()s match_state
  freezer,umh: Clean up freezer/initrd interaction
  freezer: Have {,un}lock_system_sleep() save/restore flags
  sched: Rename task_running() to task_on_cpu()
  sched/fair: Cleanup for SIS_PROP
  sched/fair: Default to false in test_idle_cores()
  sched/fair: Remove useless check in select_idle_core()
  sched/fair: Avoid double search on same cpu
  sched/fair: Remove redundant check in select_idle_smt()
  ...
2022-10-10 09:10:28 -07:00
Jakub Kicinski
e52f7c1ddf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in the left-over fixes before the net-next pull-request.

Conflicts:

drivers/net/ethernet/mediatek/mtk_ppe.c
  ae3ed15da5 ("net: ethernet: mtk_eth_soc: fix state in __mtk_foe_entry_clear")
  9d8cb4c096 ("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc")
https://lore.kernel.org/all/6cb6893b-4921-a068-4c30-1109795110bb@tessares.net/

kernel/bpf/helpers.c
  8addbfc7b3 ("bpf: Gate dynptr API behind CAP_BPF")
  5679ff2f13 ("bpf: Move bpf_loop and bpf_for_each_map_elem under CAP_BPF")
  8a67f2de9b ("bpf: expose bpf_strtol and bpf_strtoul to all program types")
https://lore.kernel.org/all/20221003201957.13149-1-daniel@iogearbox.net/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-03 17:44:18 -07:00
Kuniyuki Iwashima
7a62ed6136 af_unix: Fix memory leaks of the whole sk due to OOB skb.
syzbot reported a sequence of memory leaks, and one of them indicated we
failed to free a whole sk:

  unreferenced object 0xffff8880126e0000 (size 1088):
    comm "syz-executor419", pid 326, jiffies 4294773607 (age 12.609s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 7d 00 00 00 00 00 00 00  ........}.......
      01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............
    backtrace:
      [<000000006fefe750>] sk_prot_alloc+0x64/0x2a0 net/core/sock.c:1970
      [<0000000074006db5>] sk_alloc+0x3b/0x800 net/core/sock.c:2029
      [<00000000728cd434>] unix_create1+0xaf/0x920 net/unix/af_unix.c:928
      [<00000000a279a139>] unix_create+0x113/0x1d0 net/unix/af_unix.c:997
      [<0000000068259812>] __sock_create+0x2ab/0x550 net/socket.c:1516
      [<00000000da1521e1>] sock_create net/socket.c:1566 [inline]
      [<00000000da1521e1>] __sys_socketpair+0x1a8/0x550 net/socket.c:1698
      [<000000007ab259e1>] __do_sys_socketpair net/socket.c:1751 [inline]
      [<000000007ab259e1>] __se_sys_socketpair net/socket.c:1748 [inline]
      [<000000007ab259e1>] __x64_sys_socketpair+0x97/0x100 net/socket.c:1748
      [<000000007dedddc1>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
      [<000000007dedddc1>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
      [<000000009456679f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

We can reproduce this issue by creating two AF_UNIX SOCK_STREAM sockets,
send()ing an OOB skb to each other, and close()ing them without consuming
the OOB skbs.

  int skpair[2];

  socketpair(AF_UNIX, SOCK_STREAM, 0, skpair);

  send(skpair[0], "x", 1, MSG_OOB);
  send(skpair[1], "x", 1, MSG_OOB);

  close(skpair[0]);
  close(skpair[1]);

Currently, we free an OOB skb in unix_sock_destructor() which is called via
__sk_free(), but it's too late because the receiver's unix_sk(sk)->oob_skb
is accounted against the sender's sk->sk_wmem_alloc and __sk_free() is
called only when sk->sk_wmem_alloc is 0.

In the repro sequences, we do not consume the OOB skb, so both two sk's
sock_put() never reach __sk_free() due to the positive sk->sk_wmem_alloc.
Then, no one can consume the OOB skb nor call __sk_free(), and we finally
leak the two whole sk.

Thus, we must free the unconsumed OOB skb earlier when close()ing the
socket.

Fixes: 314001f0bf ("af_unix: Add OOB support")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-03 08:00:50 +01:00
Peilin Ye
d6e3b27cbd af_unix: Refactor unix_read_skb()
Similar to udp_read_skb(), delete the unnecessary while loop in
unix_read_skb() for readability.  Since recv_actor() cannot return a
value greater than skb->len (see sk_psock_verdict_recv()), remove the
redundant check.

Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Link: https://lore.kernel.org/r/7009141683ad6cd3785daced3e4a80ba0eb773b5.1663909008.git.peilin.ye@bytedance.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-26 11:00:19 -07:00
Peter Zijlstra
f5d39b0208 freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
2022-09-07 21:53:50 +02:00
Kirill Tkhai
de43708924 af_unix: Show number of inflight fds for sockets in TCP_LISTEN state too
TCP_LISTEN sockets is a special case. They preserve skb with a newly
connected sock till accept() makes it fully functional socket.
Receive queue of such socket may grow after connected peer
send messages there. Since these messages may contain scm_fds,
we should expose correct fdinfo::scm_fds for listening socket too.

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-22 11:34:54 +01:00
Jakub Kicinski
0076cad301 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-07-09

We've added 94 non-merge commits during the last 19 day(s) which contain
a total of 125 files changed, 5141 insertions(+), 6701 deletions(-).

The main changes are:

1) Add new way for performing BTF type queries to BPF, from Daniel Müller.

2) Add inlining of calls to bpf_loop() helper when its function callback is
   statically known, from Eduard Zingerman.

3) Implement BPF TCP CC framework usability improvements, from Jörn-Thorben Hinz.

4) Add LSM flavor for attaching per-cgroup BPF programs to existing LSM
   hooks, from Stanislav Fomichev.

5) Remove all deprecated libbpf APIs in prep for 1.0 release, from Andrii Nakryiko.

6) Add benchmarks around local_storage to BPF selftests, from Dave Marchevsky.

7) AF_XDP sample removal (given move to libxdp) and various improvements around AF_XDP
   selftests, from Magnus Karlsson & Maciej Fijalkowski.

8) Add bpftool improvements for memcg probing and bash completion, from Quentin Monnet.

9) Add arm64 JIT support for BPF-2-BPF coupled with tail calls, from Jakub Sitnicki.

10) Sockmap optimizations around throughput of UDP transmissions which have been
    improved by 61%, from Cong Wang.

11) Rework perf's BPF prologue code to remove deprecated functions, from Jiri Olsa.

12) Fix sockmap teardown path to avoid sleepable sk_psock_stop, from John Fastabend.

13) Fix libbpf's cleanup around legacy kprobe/uprobe on error case, from Chuang Wang.

14) Fix libbpf's bpf_helpers.h to work with gcc for the case of its sec/pragma
    macro, from James Hilliard.

15) Fix libbpf's pt_regs macros for riscv to use a0 for RC register, from Yixun Lan.

16) Fix bpftool to show the name of type BPF_OBJ_LINK, from Yafang Shao.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (94 commits)
  selftests/bpf: Fix xdp_synproxy build failure if CONFIG_NF_CONNTRACK=m/n
  bpf: Correctly propagate errors up from bpf_core_composites_match
  libbpf: Disable SEC pragma macro on GCC
  bpf: Check attach_func_proto more carefully in check_return_code
  selftests/bpf: Add test involving restrict type qualifier
  bpftool: Add support for KIND_RESTRICT to gen min_core_btf command
  MAINTAINERS: Add entry for AF_XDP selftests files
  selftests, xsk: Rename AF_XDP testing app
  bpf, docs: Remove deprecated xsk libbpf APIs description
  selftests/bpf: Add benchmark for local_storage RCU Tasks Trace usage
  libbpf, riscv: Use a0 for RC register
  libbpf: Remove unnecessary usdt_rel_ip assignments
  selftests/bpf: Fix few more compiler warnings
  selftests/bpf: Fix bogus uninitialized variable warning
  bpftool: Remove zlib feature test from Makefile
  libbpf: Cleanup the legacy uprobe_event on failed add/attach_event()
  libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy()
  libbpf: Cleanup the legacy kprobe_event on failed add/attach_event()
  selftests/bpf: Add type match test against kernel's task_struct
  selftests/bpf: Add nested type to type based tests
  ...
====================

Link: https://lore.kernel.org/r/20220708233145.32365-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-09 12:24:16 -07:00
Eric Dumazet
44ac441a51 af_unix: fix unix_sysctl_register() error path
We want to kfree(table) if @table has been kmalloced,
ie for non initial network namespace.

Fixes: 849d5aa3a1 ("af_unix: Do not call kmemdup() for init_net's sysctl table.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-09 12:27:33 +01:00
Kuniyuki Iwashima
cf21b355cc af_unix: Optimise hash table layout.
Commit 6dd4142fb5 ("Merge branch 'af_unix-per-netns-socket-hash'") and
commit 51bae889fe ("af_unix: Put pathname sockets in the global hash
table.") changed a hash table layout.

  Before:
    unix_socket_table [0   - 255] : abstract & pathname sockets
                      [256 - 511] : unnamed sockets

  After:
    per-netns table   [0   - 255] : abstract & pathname sockets
                      [256 - 511] : unnamed sockets
    bsd_socket_table  [0   - 255] : pathname sockets (sk_bind_node)

Now, while looking up sockets, we traverse the global table for the
pathname sockets and the first half of each per-netns hash table for
abstract sockets, where pathname sockets are also linked.  Thus, the
more pathname sockets we have, the longer we take to look up abstract
sockets.  This characteristic has been there before the layout change,
but we can improve it now.

This patch changes the per-netns hash table's layout so that sockets not
requiring lookup reside in the first half and do not impact the lookup of
abstract sockets.

    per-netns table   [0   - 255] : pathname & unnamed sockets
                      [256 - 511] : abstract sockets
    bsd_socket_table  [0   - 255] : pathname sockets (sk_bind_node)

We have run a test that bind()s 100,000 abstract/pathname sockets for
each, bind()s an abstract socket 100,000 times and measures the time
on __unix_find_socket_byname().  The result shows that the patch makes
each lookup faster.

  Without this patch:
    $ sudo ./funclatency -p 2278 --microseconds __unix_find_socket_byname.isra.44
     usec                : count    distribution
         0 -> 1          : 0        |                                        |
         2 -> 3          : 0        |                                        |
         4 -> 7          : 0        |                                        |
         8 -> 15         : 126      |                                        |
        16 -> 31         : 1438     |*                                       |
        32 -> 63         : 4150     |***                                     |
        64 -> 127        : 9049     |*******                                 |
       128 -> 255        : 37704    |*******************************         |
       256 -> 511        : 47533    |****************************************|

  With this patch:
    $ sudo ./funclatency -p 3648 --microseconds __unix_find_socket_byname.isra.46
     usec                : count    distribution
         0 -> 1          : 109      |                                        |
         2 -> 3          : 318      |                                        |
         4 -> 7          : 725      |                                        |
         8 -> 15         : 2501     |*                                       |
        16 -> 31         : 3061     |**                                      |
        32 -> 63         : 4028     |***                                     |
        64 -> 127        : 9312     |*******                                 |
       128 -> 255        : 51372    |****************************************|
       256 -> 511        : 28574    |**********************                  |

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20220705233715.759-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-07-07 13:19:01 +02:00
Kuniyuki Iwashima
51bae889fe af_unix: Put pathname sockets in the global hash table.
Commit cf2f225e26 ("af_unix: Put a socket into a per-netns hash table.")
accidentally broke user API for pathname sockets.  A socket was able to
connect() to a pathname socket whose file was visible even if they were in
different network namespaces.

The commit puts all sockets into a per-netns hash table.  As a result,
connect() to a pathname socket in a different netns fails to find it in the
caller's per-netns hash table and returns -ECONNREFUSED even when the task
can view the peer socket file.

We can reproduce this issue by:

  Console A:

    # python3
    >>> from socket import *
    >>> s = socket(AF_UNIX, SOCK_STREAM, 0)
    >>> s.bind('test')
    >>> s.listen(32)

  Console B:

    # ip netns add test
    # ip netns exec test sh
    # python3
    >>> from socket import *
    >>> s = socket(AF_UNIX, SOCK_STREAM, 0)
    >>> s.connect('test')

Note when dumping sockets by sock_diag, procfs, and bpf_iter, they are
filtered only by netns.  In other words, even if they are visible and
connect()able, all sockets in different netns are skipped while iterating
sockets.  Thus, we need a fix only for finding a peer pathname socket.

This patch adds a global hash table for pathname sockets, links them with
sk_bind_node, and uses it in unix_find_socket_byinode().  By doing so, we
can keep sockets in per-netns hash tables and dump them easily.

Thanks to Sachin Sant and Leonard Crestez for reports, logs and a reproducer.

Fixes: cf2f225e26 ("af_unix: Put a socket into a per-netns hash table.")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Reported-by: Leonard Crestez <cdleonard@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Tested-by: Leonard Crestez <cdleonard@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-07-05 11:34:58 +02:00
Kuniyuki Iwashima
849d5aa3a1 af_unix: Do not call kmemdup() for init_net's sysctl table.
While setting up init_net's sysctl table, we need not duplicate the
global table and can use it directly as ipv4_sysctl_init_net() does.

Unlike IPv4, AF_UNIX does not have a huge sysctl table for now, so it
cannot be a problem, but this patch makes code consistent.

Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20220627233627.51646-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-28 20:58:57 -07:00
Kuniyuki Iwashima
2f7ca90a01 af_unix: Remove unix_table_locks.
unix_table_locks are to protect the global hash table, unix_socket_table.
The previous commit removed it, so let's clean up the unnecessary locks.

Here is a test result on EC2 c5.9xlarge where 10 processes run concurrently
in different netns and bind 100,000 sockets for each.

  without this series : 1m 38s
  with this series    :    11s

It is ~10x faster because the global hash table is split into 10 netns in
this case.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-22 12:59:43 +01:00
Kuniyuki Iwashima
cf2f225e26 af_unix: Put a socket into a per-netns hash table.
This commit replaces the global hash table with a per-netns one and removes
the global one.

We now link a socket in each netns's hash table so we can save some netns
comparisons when iterating through a hash bucket.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-22 12:59:43 +01:00
Kuniyuki Iwashima
79b05beaa5 af_unix: Acquire/Release per-netns hash table's locks.
This commit adds extra spin_lock/spin_unlock() for a per-netns
hash table inside the existing ones for unix_table_locks.

As of this commit, sockets are still linked in the global hash
table.  After putting sockets in a per-netns hash table and
removing the old one in the next patch, we remove the global
locks in the last patch.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-22 12:59:43 +01:00
Kuniyuki Iwashima
b6e8113830 af_unix: Define a per-netns hash table.
This commit adds a per netns hash table for AF_UNIX, which size is fixed
as UNIX_HASH_SIZE for now.

The first implementation defines a per-netns hash table as a single array
of lock and list:

	struct unix_hashbucket {
		spinlock_t		lock;
		struct hlist_head	head;
	};

	struct netns_unix {
		struct unix_hashbucket	*hash;
		...
	};

But, Eric pointed out memory cost that the structure has holes because of
sizeof(spinlock_t), which is 4 (or more if LOCKDEP is enabled). [0]  It
could be expensive on a host with thousands of netns and few AF_UNIX
sockets.  For this reason, a per-netns hash table uses two dense arrays.

	struct unix_table {
		spinlock_t		*locks;
		struct hlist_head	*buckets;
	};

	struct netns_unix {
		struct unix_table	table;
		...
	};

Note the length of the list has a significant impact rather than lock
contention, so having shared locks can be an option.  But, per-netns
locks and lists still perform better than the global locks and per-netns
lists. [1]

Also, this patch adds a change so that struct netns_unix disappears from
struct net if CONFIG_UNIX is disabled.

[0]: https://lore.kernel.org/netdev/CANn89iLVxO5aqx16azNU7p7Z-nz5NrnM5QTqOzueVxEnkVTxyg@mail.gmail.com/
[1]: https://lore.kernel.org/netdev/20220617175215.1769-1-kuniyu@amazon.com/

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-22 12:59:43 +01:00
Kuniyuki Iwashima
f302d180c6 af_unix: Include the whole hash table size in UNIX_HASH_SIZE.
Currently, the size of AF_UNIX hash table is UNIX_HASH_SIZE * 2,
the first half for bind()ed sockets and the second half for unbound
ones.  UNIX_HASH_SIZE * 2 is used to define the table and iterate
over it.

In some places, we use ARRAY_SIZE(unix_socket_table) instead of
UNIX_HASH_SIZE * 2.  However, we cannot use it anymore because we
will allocate the hash table dynamically.  Then, we would have to
add UNIX_HASH_SIZE * 2 in many places, which would be troublesome.

This patch adapts the UNIX_HASH_SIZE definition to include bound
and unbound sockets and defines a new UNIX_HASH_MOD macro to ease
calculations.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-22 12:59:43 +01:00
Kuniyuki Iwashima
340c3d3371 af_unix: Clean up some sock_net() uses.
Some functions define a net pointer only for one-shot use.  Others call
sock_net() redundantly even when a net pointer is available.  Let's fix
these and make the code simpler.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-22 12:59:43 +01:00
Cong Wang
965b57b469 net: Introduce a new proto_ops ->read_skb()
Currently both splice() and sockmap use ->read_sock() to
read skb from receive queue, but for sockmap we only read
one entire skb at a time, so ->read_sock() is too conservative
to use. Introduce a new proto_ops ->read_skb() which supports
this sematic, with this we can finally pass the ownership of
skb to recv actors.

For non-TCP protocols, all ->read_sock() can be simply
converted to ->read_skb().

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220615162014.89193-3-xiyou.wangcong@gmail.com
2022-06-20 14:05:52 +02:00
Eric Dumazet
dd29c67dbb af_unix: use DEBUG_NET_WARN_ON_ONCE()
Replace four WARN_ON() that have not triggered recently
with DEBUG_NET_WARN_ON_ONCE().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-09 21:53:56 -07:00
Kuniyuki Iwashima
662a80946c af_unix: Fix a data-race in unix_dgram_peer_wake_me().
unix_dgram_poll() calls unix_dgram_peer_wake_me() without `other`'s
lock held and check if its receive queue is full.  Here we need to
use unix_recvq_full_lockless() instead of unix_recvq_full(), otherwise
KCSAN will report a data-race.

Fixes: 7d267278a9 ("unix: avoid use-after-free in ep_remove_wait_queue")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20220605232325.11804-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-06-07 12:07:46 +02:00
Linus Torvalds
7e062cda7d Networking changes for 5.19.
Core
 ----
 
  - Support TCPv6 segmentation offload with super-segments larger than
    64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).
 
  - Generalize skb freeing deferral to per-cpu lists, instead of
    per-socket lists.
 
  - Add a netdev statistic for packets dropped due to L2 address
    mismatch (rx_otherhost_dropped).
 
  - Continue work annotating skb drop reasons.
 
  - Accept alternative netdev names (ALT_IFNAME) in more netlink
    requests.
 
  - Add VLAN support for AF_PACKET SOCK_RAW GSO.
 
  - Allow receiving skb mark from the socket as a cmsg.
 
  - Enable memcg accounting for veth queues, sysctl tables and IPv6.
 
 BPF
 ---
 
  - Add libbpf support for User Statically-Defined Tracing (USDTs).
 
  - Speed up symbol resolution for kprobes multi-link attachments.
 
  - Support storing typed pointers to referenced and unreferenced
    objects in BPF maps.
 
  - Add support for BPF link iterator.
 
  - Introduce access to remote CPU map elements in BPF per-cpu map.
 
  - Allow middle-of-the-road settings for the
    kernel.unprivileged_bpf_disabled sysctl.
 
  - Implement basic types of dynamic pointers e.g. to allow for
    dynamically sized ringbuf reservations without extra memory copies.
 
 Protocols
 ---------
 
  - Retire port only listening_hash table, add a second bind table
    hashed by port and address. Avoid linear list walk when binding
    to very popular ports (e.g. 443).
 
  - Add bridge FDB bulk flush filtering support allowing user space
    to remove all FDB entries matching a condition.
 
  - Introduce accept_unsolicited_na sysctl for IPv6 to implement
    router-side changes for RFC9131.
 
  - Support for MPTCP path manager in user space.
 
  - Add MPTCP support for fallback to regular TCP for connections
    that have never connected additional subflows or transmitted
    out-of-sequence data (partial support for RFC8684 fallback).
 
  - Avoid races in MPTCP-level window tracking, stabilize and improve
    throughput.
 
  - Support lockless operation of GRE tunnels with seq numbers enabled.
 
  - WiFi support for host based BSS color collision detection.
 
  - Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.
 
  - Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).
 
  - Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).
 
  - Allow matching on the number of VLAN tags via tc-flower.
 
  - Add tracepoint for tcp_set_ca_state().
 
 Driver API
 ----------
 
  - Improve error reporting from classifier and action offload.
 
  - Add support for listing line cards in switches (devlink).
 
  - Add helpers for reporting page pool statistics with ethtool -S.
 
  - Add support for reading clock cycles when using PTP virtual clocks,
    instead of having the driver convert to time before reporting.
    This makes it possible to report time from different vclocks.
 
  - Support configuring low-latency Tx descriptor push via ethtool.
 
  - Separate Clause 22 and Clause 45 MDIO accesses more explicitly.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
    - Sunplus SP7021 SoC (sp7021_emac)
    - Add support for Renesas RZ/V2M (in ravb)
    - Add support for MediaTek mt7986 switches (in mtk_eth_soc)
 
  - Ethernet PHYs:
    - ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
    - TI DP83TD510 PHY
    - Microchip LAN8742/LAN88xx PHYs
 
  - WiFi:
    - Driver for pureLiFi X, XL, XC devices (plfxlc)
    - Driver for Silicon Labs devices (wfx)
    - Support for WCN6750 (in ath11k)
    - Support Realtek 8852ce devices (in rtw89)
 
  - Mobile:
    - MediaTek T700 modems (Intel 5G 5000 M.2 cards)
 
  - CAN:
   - ctucanfd: add support for CTU CAN FD open-source IP core
     from Czech Technical University in Prague
 
 Drivers
 -------
 
  - Delete a number of old drivers still using virt_to_bus().
 
  - Ethernet NICs:
    - intel: support TSO on tunnels MPLS
    - broadcom: support multi-buffer XDP
    - nfp: support VF rate limiting
    - sfc: use hardware tx timestamps for more than PTP
    - mlx5: multi-port eswitch support
    - hyper-v: add support for XDP_REDIRECT
    - atlantic: XDP support (including multi-buffer)
    - macb: improve real-time perf by deferring Tx processing to NAPI
 
  - High-speed Ethernet switches:
    - mlxsw: implement basic line card information querying
    - prestera: add support for traffic policing on ingress and egress
 
  - Embedded Ethernet switches:
    - lan966x: add support for packet DMA (FDMA)
    - lan966x: add support for PTP programmable pins
    - ti: cpsw_new: enable bc/mc storm prevention
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - Wake-on-WLAN support for QCA6390 and WCN6855
    - device recovery (firmware restart) support
    - support setting Specific Absorption Rate (SAR) for WCN6855
    - read country code from SMBIOS for WCN6855/QCA6390
    - enable keep-alive during WoWLAN suspend
    - implement remain-on-channel support
 
  - MediaTek WiFi (mt76):
    - support Wireless Ethernet Dispatch offloading packet movement
      between the Ethernet switch and WiFi interfaces
    - non-standard VHT MCS10-11 support
    - mt7921 AP mode support
    - mt7921 IPv6 NS offload support
 
  - Ethernet PHYs:
    - micrel: ksz9031/ksz9131: cabletest support
    - lan87xx: SQI support for T1 PHYs
    - lan937x: add interrupt support for link detection
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core
  ----

   - Support TCPv6 segmentation offload with super-segments larger than
     64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).

   - Generalize skb freeing deferral to per-cpu lists, instead of
     per-socket lists.

   - Add a netdev statistic for packets dropped due to L2 address
     mismatch (rx_otherhost_dropped).

   - Continue work annotating skb drop reasons.

   - Accept alternative netdev names (ALT_IFNAME) in more netlink
     requests.

   - Add VLAN support for AF_PACKET SOCK_RAW GSO.

   - Allow receiving skb mark from the socket as a cmsg.

   - Enable memcg accounting for veth queues, sysctl tables and IPv6.

  BPF
  ---

   - Add libbpf support for User Statically-Defined Tracing (USDTs).

   - Speed up symbol resolution for kprobes multi-link attachments.

   - Support storing typed pointers to referenced and unreferenced
     objects in BPF maps.

   - Add support for BPF link iterator.

   - Introduce access to remote CPU map elements in BPF per-cpu map.

   - Allow middle-of-the-road settings for the
     kernel.unprivileged_bpf_disabled sysctl.

   - Implement basic types of dynamic pointers e.g. to allow for
     dynamically sized ringbuf reservations without extra memory copies.

  Protocols
  ---------

   - Retire port only listening_hash table, add a second bind table
     hashed by port and address. Avoid linear list walk when binding to
     very popular ports (e.g. 443).

   - Add bridge FDB bulk flush filtering support allowing user space to
     remove all FDB entries matching a condition.

   - Introduce accept_unsolicited_na sysctl for IPv6 to implement
     router-side changes for RFC9131.

   - Support for MPTCP path manager in user space.

   - Add MPTCP support for fallback to regular TCP for connections that
     have never connected additional subflows or transmitted
     out-of-sequence data (partial support for RFC8684 fallback).

   - Avoid races in MPTCP-level window tracking, stabilize and improve
     throughput.

   - Support lockless operation of GRE tunnels with seq numbers enabled.

   - WiFi support for host based BSS color collision detection.

   - Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.

   - Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).

   - Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).

   - Allow matching on the number of VLAN tags via tc-flower.

   - Add tracepoint for tcp_set_ca_state().

  Driver API
  ----------

   - Improve error reporting from classifier and action offload.

   - Add support for listing line cards in switches (devlink).

   - Add helpers for reporting page pool statistics with ethtool -S.

   - Add support for reading clock cycles when using PTP virtual clocks,
     instead of having the driver convert to time before reporting. This
     makes it possible to report time from different vclocks.

   - Support configuring low-latency Tx descriptor push via ethtool.

   - Separate Clause 22 and Clause 45 MDIO accesses more explicitly.

  New hardware / drivers
  ----------------------

   - Ethernet:
      - Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
      - Sunplus SP7021 SoC (sp7021_emac)
      - Add support for Renesas RZ/V2M (in ravb)
      - Add support for MediaTek mt7986 switches (in mtk_eth_soc)

   - Ethernet PHYs:
      - ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
      - TI DP83TD510 PHY
      - Microchip LAN8742/LAN88xx PHYs

   - WiFi:
      - Driver for pureLiFi X, XL, XC devices (plfxlc)
      - Driver for Silicon Labs devices (wfx)
      - Support for WCN6750 (in ath11k)
      - Support Realtek 8852ce devices (in rtw89)

   - Mobile:
      - MediaTek T700 modems (Intel 5G 5000 M.2 cards)

   - CAN:
      - ctucanfd: add support for CTU CAN FD open-source IP core from
        Czech Technical University in Prague

  Drivers
  -------

   - Delete a number of old drivers still using virt_to_bus().

   - Ethernet NICs:
      - intel: support TSO on tunnels MPLS
      - broadcom: support multi-buffer XDP
      - nfp: support VF rate limiting
      - sfc: use hardware tx timestamps for more than PTP
      - mlx5: multi-port eswitch support
      - hyper-v: add support for XDP_REDIRECT
      - atlantic: XDP support (including multi-buffer)
      - macb: improve real-time perf by deferring Tx processing to NAPI

   - High-speed Ethernet switches:
      - mlxsw: implement basic line card information querying
      - prestera: add support for traffic policing on ingress and egress

   - Embedded Ethernet switches:
      - lan966x: add support for packet DMA (FDMA)
      - lan966x: add support for PTP programmable pins
      - ti: cpsw_new: enable bc/mc storm prevention

   - Qualcomm 802.11ax WiFi (ath11k):
      - Wake-on-WLAN support for QCA6390 and WCN6855
      - device recovery (firmware restart) support
      - support setting Specific Absorption Rate (SAR) for WCN6855
      - read country code from SMBIOS for WCN6855/QCA6390
      - enable keep-alive during WoWLAN suspend
      - implement remain-on-channel support

   - MediaTek WiFi (mt76):
      - support Wireless Ethernet Dispatch offloading packet movement
        between the Ethernet switch and WiFi interfaces
      - non-standard VHT MCS10-11 support
      - mt7921 AP mode support
      - mt7921 IPv6 NS offload support

   - Ethernet PHYs:
      - micrel: ksz9031/ksz9131: cabletest support
      - lan87xx: SQI support for T1 PHYs
      - lan937x: add interrupt support for link detection"

* tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1809 commits)
  ptp: ocp: Add firmware header checks
  ptp: ocp: fix PPS source selector debugfs reporting
  ptp: ocp: add .init function for sma_op vector
  ptp: ocp: vectorize the sma accessor functions
  ptp: ocp: constify selectors
  ptp: ocp: parameterize input/output sma selectors
  ptp: ocp: revise firmware display
  ptp: ocp: add Celestica timecard PCI ids
  ptp: ocp: Remove #ifdefs around PCI IDs
  ptp: ocp: 32-bit fixups for pci start address
  Revert "net/smc: fix listen processing for SMC-Rv2"
  ath6kl: Use cc-disable-warning to disable -Wdangling-pointer
  selftests/bpf: Dynptr tests
  bpf: Add dynptr data slices
  bpf: Add bpf_dynptr_read and bpf_dynptr_write
  bpf: Dynptr support for ring buffers
  bpf: Add bpf_dynptr_from_mem for local dynptrs
  bpf: Add verifier support for dynptrs
  bpf: Suppress 'passing zero to PTR_ERR' warning
  bpf: Introduce bpf_arch_text_invalidate for bpf_prog_pack
  ...
2022-05-25 12:22:58 -07:00
Kees Cook
b146cbf2e3 af_unix: Silence randstruct GCC plugin warning
While preparing for Clang randstruct support (which duplicated many of
the warnings the randstruct GCC plugin warned about), one strange one
remained only for the randstruct GCC plugin. Eliminating this rids
the plugin of the last exception.

It seems the plugin is happy to dereference individual members of
a cross-struct cast, but it is upset about casting to a whole object
pointer. This only manifests in one place in the kernel, so just replace
the variable with individual member accesses. There is no change in
executable instruction output.

Drop the last exception from the randstruct GCC plugin.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Cong Wang <cong.wang@bytedance.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: netdev@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/lkml/20220511022217.58586-1-kuniyu@amazon.co.jp
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/lkml/20220511151542.4cb3ff17@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-16 16:02:21 -07:00
Oliver Hartkopp
ec095263a9 net: remove noblock parameter from recvmsg() entities
The internal recvmsg() functions have two parameters 'flags' and 'noblock'
that were merged inside skb_recv_datagram(). As a follow up patch to commit
f4b41f062c ("net: remove noblock parameter from skb_recv_datagram()")
this patch removes the separate 'noblock' parameter for recvmsg().

Analogue to the referenced patch for skb_recv_datagram() the 'flags' and
'noblock' parameters are unnecessarily split up with e.g.

err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
                           flags & ~MSG_DONTWAIT, &addr_len);

or in

err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
                      sk, msg, size, flags & MSG_DONTWAIT,
                      flags & ~MSG_DONTWAIT, &addr_len);

instead of simply using only flags all the time and check for MSG_DONTWAIT
where needed (to preserve for the formerly separated no(n)block condition).

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-04-12 15:00:25 +02:00
Oliver Hartkopp
f4b41f062c net: remove noblock parameter from skb_recv_datagram()
skb_recv_datagram() has two parameters 'flags' and 'noblock' that are
merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)'

As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags'
into 'flags' and 'noblock' with finally obsolete bit operations like this:

skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc);

And this is not even done consistently with the 'flags' parameter.

This patch removes the obsolete and costly splitting into two parameters
and only performs bit operations when really needed on the caller side.

One missing conversion thankfully reported by kernel test robot. I missed
to enable kunit tests to build the mctp code.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-06 13:45:26 +01:00
Jakub Kicinski
89695196f0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in overtime fixes, no conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-23 10:53:49 -07:00
Kuniyuki Iwashima
4edf21aa94 af_unix: Remove unnecessary brackets around CONFIG_AF_UNIX_OOB.
Let's remove unnecessary brackets around CONFIG_AF_UNIX_OOB.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/r/20220317032308.65372-1-kuniyu@amazon.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-18 14:06:39 -07:00
Kuniyuki Iwashima
d9a232d435 af_unix: Support POLLPRI for OOB.
The commit 314001f0bf ("af_unix: Add OOB support") introduced OOB for
AF_UNIX, but it lacks some changes for POLLPRI.  Let's add the missing
piece.

In the selftest, normal datagrams are sent followed by OOB data, so this
commit replaces `POLLIN | POLLPRI` with just `POLLPRI` in the first test
case.

Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-18 13:30:52 +00:00
Kuniyuki Iwashima
e82025c623 af_unix: Fix some data-races around unix_sk(sk)->oob_skb.
Out-of-band data automatically places a "mark" showing wherein the
sequence the out-of-band data would have been.  If the out-of-band data
implies cancelling everything sent so far, the "mark" is helpful to flush
them.  When the socket's read pointer reaches the "mark", the ioctl() below
sets a non zero value to the arg `atmark`:

The out-of-band data is queued in sk->sk_receive_queue as well as ordinary
data and also saved in unix_sk(sk)->oob_skb.  It can be used to test if the
head of the receive queue is the out-of-band data meaning the socket is at
the "mark".

While testing that, unix_ioctl() reads unix_sk(sk)->oob_skb locklessly.
Thus, all accesses to oob_skb need some basic protection to avoid
load/store tearing which KCSAN detects when these are called concurrently:

  - ioctl(fd_a, SIOCATMARK, &atmark, sizeof(atmark))
  - send(fd_b_connected_to_a, buf, sizeof(buf), MSG_OOB)

BUG: KCSAN: data-race in unix_ioctl / unix_stream_sendmsg

write to 0xffff888003d9cff0 of 8 bytes by task 175 on cpu 1:
 unix_stream_sendmsg (net/unix/af_unix.c:2087 net/unix/af_unix.c:2191)
 sock_sendmsg (net/socket.c:705 net/socket.c:725)
 __sys_sendto (net/socket.c:2040)
 __x64_sys_sendto (net/socket.c:2048)
 do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)

read to 0xffff888003d9cff0 of 8 bytes by task 176 on cpu 0:
 unix_ioctl (net/unix/af_unix.c:3101 (discriminator 1))
 sock_do_ioctl (net/socket.c:1128)
 sock_ioctl (net/socket.c:1242)
 __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:874 fs/ioctl.c:860 fs/ioctl.c:860)
 do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)

value changed: 0xffff888003da0c00 -> 0xffff888003da0d00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 176 Comm: unix_race_oob_i Not tainted 5.17.0-rc5-59529-g83dc4c2af682 #12
Hardware name: Red Hat KVM, BIOS 1.11.0-2.amzn2 04/01/2014

Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-18 13:30:52 +00:00
Jakub Kicinski
caaba96131 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-01-24

We've added 80 non-merge commits during the last 14 day(s) which contain
a total of 128 files changed, 4990 insertions(+), 895 deletions(-).

The main changes are:

1) Add XDP multi-buffer support and implement it for the mvneta driver,
   from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen.

2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc
   infra, from Kumar Kartikeya Dwivedi.

3) Extend BPF cgroup programs to export custom ret value to userspace via
   two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu.

4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima.

5) Complete missing UAPI BPF helper description and change bpf_doc.py script
   to enforce consistent & complete helper documentation, from Usama Arif.

6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to
   follow tc-based APIs, from Andrii Nakryiko.

7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu.

8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters
   and setters, from Christy Lee.

9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to
   reduce overhead, from Kui-Feng Lee.

10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new()
    utility function, from Mauricio Vásquez.

11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau.

12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits)
  selftests, bpf: Do not yet switch to new libbpf XDP APIs
  selftests, xsk: Fix rx_full stats test
  bpf: Fix flexible_array.cocci warnings
  xdp: disable XDP_REDIRECT for xdp frags
  bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
  bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
  net: xdp: introduce bpf_xdp_pointer utility routine
  bpf: generalise tail call map compatibility check
  libbpf: Add SEC name for xdp frags programs
  bpf: selftests: update xdp_adjust_tail selftest to include xdp frags
  bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
  bpf: introduce frags support to bpf_prog_test_run_xdp()
  bpf: move user_size out of bpf_test_init
  bpf: add frags support to xdp copy helpers
  bpf: add frags support to the bpf_xdp_adjust_tail() API
  bpf: introduce bpf_xdp_get_buff_len helper
  net: mvneta: enable jumbo frames if the loaded XDP program support frags
  bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program
  net: mvneta: add frags support to XDP_TX
  xdp: add frags support to xdp_return_{buff/frame}
  ...
====================

Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-24 15:42:29 -08:00
Kuniyuki Iwashima
eb7d8f1d9e bpf: Support bpf_(get|set)sockopt() in bpf unix iter.
This patch makes bpf_(get|set)sockopt() available when iterating AF_UNIX
sockets.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/r/20220113002849.4384-4-kuniyu@amazon.co.jp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-18 15:45:06 -08:00
Kuniyuki Iwashima
855d8e77ff bpf: af_unix: Use batching algorithm in bpf unix iter.
The commit 04c7820b77 ("bpf: tcp: Bpf iter batching and lock_sock")
introduces the batching algorithm to iterate TCP sockets with more
consistency.

This patch uses the same algorithm to iterate AF_UNIX sockets.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/r/20220113002849.4384-3-kuniyu@amazon.co.jp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-18 15:45:06 -08:00
Kuniyuki Iwashima
4408d55a64 af_unix: Refactor unix_next_socket().
Currently, unix_next_socket() is overloaded depending on the 2nd argument.
If it is NULL, unix_next_socket() returns the first socket in the hash.  If
not NULL, it returns the next socket in the same hash list or the first
socket in the next non-empty hash list.

This patch refactors unix_next_socket() into two functions unix_get_first()
and unix_get_next().  unix_get_first() newly acquires a lock and returns
the first socket in the list.  unix_get_next() returns the next socket in a
list or releases a lock and falls back to unix_get_first().

In the following patch, bpf iter holds entire sockets in a list and always
releases the lock before .show().  It always calls unix_get_first() to
acquire a lock in each iteration.  So, this patch makes the change easier
to follow.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/r/20220113002849.4384-2-kuniyu@amazon.co.jp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-18 15:45:06 -08:00
Eric Dumazet
9d6d7f1cb6 af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress
wait_for_unix_gc() reads unix_tot_inflight & gc_in_progress
without synchronization.

Adds READ_ONCE()/WRITE_ONCE() and their associated comments
to better document the intent.

BUG: KCSAN: data-race in unix_inflight / wait_for_unix_gc

write to 0xffffffff86e2b7c0 of 4 bytes by task 9380 on cpu 0:
 unix_inflight+0x1e8/0x260 net/unix/scm.c:63
 unix_attach_fds+0x10c/0x1e0 net/unix/scm.c:121
 unix_scm_to_skb net/unix/af_unix.c:1674 [inline]
 unix_dgram_sendmsg+0x679/0x16b0 net/unix/af_unix.c:1817
 unix_seqpacket_sendmsg+0xcc/0x110 net/unix/af_unix.c:2258
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffffff86e2b7c0 of 4 bytes by task 9375 on cpu 1:
 wait_for_unix_gc+0x24/0x160 net/unix/garbage.c:196
 unix_dgram_sendmsg+0x8e/0x16b0 net/unix/af_unix.c:1772
 unix_seqpacket_sendmsg+0xcc/0x110 net/unix/af_unix.c:2258
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000002 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9375 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 9915672d41 ("af_unix: limit unix_tot_inflight")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220114164328.2038499-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-14 18:31:37 -08:00
David S. Miller
e63a023489 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-12-30

The following pull-request contains BPF updates for your *net-next* tree.

We've added 72 non-merge commits during the last 20 day(s) which contain
a total of 223 files changed, 3510 insertions(+), 1591 deletions(-).

The main changes are:

1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii.

2) Beautify and de-verbose verifier logs, from Christy.

3) Composable verifier types, from Hao.

4) bpf_strncmp helper, from Hou.

5) bpf.h header dependency cleanup, from Jakub.

6) get_func_[arg|ret|arg_cnt] helpers, from Jiri.

7) Sleepable local storage, from KP.

8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-31 14:35:40 +00:00
Jakub Kicinski
b6459415b3 net: Don't include filter.h from net/sock.h
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-12-29 08:48:14 -08:00
Joanne Koong
cec16052d5 net: Enable max_dgram_qlen unix sysctl to be configurable by non-init user namespaces
This patch enables the "/proc/sys/net/unix/max_dgram_qlen" sysctl to be
exposed to non-init user namespaces. max_dgram_qlen is used as the default
"sk_max_ack_backlog" value for when a unix socket is created.

Currently, when a networking namespace is initialized, its unix sysctls
are exposed only if the user namespace that "owns" it is the init user
namespace. If there is an non-init user namespace that "owns" a networking
namespace (for example, in the case after we call clone() with both
CLONE_NEWUSER and CLONE_NEWNET set), the sysctls are hidden from view
and not configurable.

Exposing the unix sysctl is safe because any changes made to it will be
limited in scope to the networking namespace the non-init user namespace
"owns" and has privileges over (changes won't affect any other net
namespace). There is also no possibility of a non-privileged user namespace
messing up the net namespace sysctls it shares with its parent user namespace.
When a new user namespace is created without unsharing the network namespace
(eg calling clone()  with CLONE_NEWUSER), the new user namespace shares its
parent's network namespace. Write access is protected by the mode set
in the sysctl's ctl_table (and enforced by procfs). Here in the case of
"max_dgram_qlen", 0644 is set; only the user owner has write access.

v1 -> v2:
* Add more detail to commit message, specify the
"/proc/sys/net/unix/max_dgram_qlen" sysctl in commit message.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-13 12:47:47 +00:00
Kuniyuki Iwashima
9acbc584c3 af_unix: Relax race in unix_autobind().
When we bind an AF_UNIX socket without a name specified, the kernel selects
an available one from 0x00000 to 0xFFFFF.  unix_autobind() starts searching
from a number in the 'static' variable and increments it after acquiring
two locks.

If multiple processes try autobind, they obtain the same lock and check if
a socket in the hash list has the same name.  If not, one process uses it,
and all except one end up retrying the _next_ number (actually not, it may
be incremented by the other processes).  The more we autobind sockets in
parallel, the longer the latency gets.  We can avoid such a race by
searching for a name from a random number.

These show latency in unix_autobind() while 64 CPUs are simultaneously
autobind-ing 1024 sockets for each.

  Without this patch:

     usec          : count     distribution
        0          : 1176     |***                                     |
        2          : 3655     |***********                             |
        4          : 4094     |*************                           |
        6          : 3831     |************                            |
        8          : 3829     |************                            |
        10         : 3844     |************                            |
        12         : 3638     |***********                             |
        14         : 2992     |*********                               |
        16         : 2485     |*******                                 |
        18         : 2230     |*******                                 |
        20         : 2095     |******                                  |
        22         : 1853     |*****                                   |
        24         : 1827     |*****                                   |
        26         : 1677     |*****                                   |
        28         : 1473     |****                                    |
        30         : 1573     |*****                                   |
        32         : 1417     |****                                    |
        34         : 1385     |****                                    |
        36         : 1345     |****                                    |
        38         : 1344     |****                                    |
        40         : 1200     |***                                     |

  With this patch:

     usec          : count     distribution
        0          : 1855     |******                                  |
        2          : 6464     |*********************                   |
        4          : 9936     |********************************        |
        6          : 12107    |****************************************|
        8          : 10441    |**********************************      |
        10         : 7264     |***********************                 |
        12         : 4254     |**************                          |
        14         : 2538     |********                                |
        16         : 1596     |*****                                   |
        18         : 1088     |***                                     |
        20         : 800      |**                                      |
        22         : 670      |**                                      |
        24         : 601      |*                                       |
        26         : 562      |*                                       |
        28         : 525      |*                                       |
        30         : 446      |*                                       |
        32         : 378      |*                                       |
        34         : 337      |*                                       |
        36         : 317      |*                                       |
        38         : 314      |*                                       |
        40         : 298      |                                        |

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:58 -08:00
Kuniyuki Iwashima
afd20b9290 af_unix: Replace the big lock with small locks.
The hash table of AF_UNIX sockets is protected by the single lock.  This
patch replaces it with per-hash locks.

The effect is noticeable when we handle multiple sockets simultaneously.
Here is a test result on an EC2 c5.24xlarge instance.  It shows latency
(under 10us only) in unix_insert_unbound_socket() while 64 CPUs creating
1024 sockets for each in parallel.

  Without this patch:

     nsec          : count     distribution
        0          : 179      |                                        |
        500        : 3021     |*********                               |
        1000       : 6271     |*******************                     |
        1500       : 6318     |*******************                     |
        2000       : 5828     |*****************                       |
        2500       : 5124     |***************                         |
        3000       : 4426     |*************                           |
        3500       : 3672     |***********                             |
        4000       : 3138     |*********                               |
        4500       : 2811     |********                                |
        5000       : 2384     |*******                                 |
        5500       : 2023     |******                                  |
        6000       : 1954     |*****                                   |
        6500       : 1737     |*****                                   |
        7000       : 1749     |*****                                   |
        7500       : 1520     |****                                    |
        8000       : 1469     |****                                    |
        8500       : 1394     |****                                    |
        9000       : 1232     |***                                     |
        9500       : 1138     |***                                     |
        10000      : 994      |***                                     |

  With this patch:

     nsec          : count     distribution
        0          : 1634     |****                                    |
        500        : 13170    |****************************************|
        1000       : 13156    |*************************************** |
        1500       : 9010     |***************************             |
        2000       : 6363     |*******************                     |
        2500       : 4443     |*************                           |
        3000       : 3240     |*********                               |
        3500       : 2549     |*******                                 |
        4000       : 1872     |*****                                   |
        4500       : 1504     |****                                    |
        5000       : 1247     |***                                     |
        5500       : 1035     |***                                     |
        6000       : 889      |**                                      |
        6500       : 744      |**                                      |
        7000       : 634      |*                                       |
        7500       : 498      |*                                       |
        8000       : 433      |*                                       |
        8500       : 355      |*                                       |
        9000       : 336      |*                                       |
        9500       : 284      |                                        |
        10000      : 243      |                                        |

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:58 -08:00
Kuniyuki Iwashima
e6b4b87389 af_unix: Save hash in sk_hash.
To replace unix_table_lock with per-hash locks in the next patch, we need
to save a hash in each socket because /proc/net/unix or BPF prog iterate
sockets while holding a hash table lock and release it later in a different
function.

Currently, we store a real/pseudo hash in struct unix_address.  However, we
do not allocate it to unbound sockets, nor should we do just for that.  For
this purpose, we can use sk_hash.  Then, we no longer use the hash field in
struct unix_address and can remove it.

Also, this patch does
  - rename unix_insert_socket() to unix_insert_unbound_socket()
  - remove the redundant list argument from __unix_insert_socket() and
     unix_insert_unbound_socket()
  - use 'unsigned int' instead of 'unsigned' in __unix_set_addr_hash()
  - remove 'inline' from unix_remove_socket() and
     unix_insert_unbound_socket().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:57 -08:00
Kuniyuki Iwashima
f452be496a af_unix: Add helpers to calculate hashes.
This patch adds three helper functions that calculate hashes for unbound
sockets and bound sockets with BSD/abstract addresses.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:57 -08:00
Kuniyuki Iwashima
5ce7ab4961 af_unix: Remove UNIX_ABSTRACT() macro and test sun_path[0] instead.
In BSD and abstract address cases, we store sockets in the hash table with
keys between 0 and UNIX_HASH_SIZE - 1.  However, the hash saved in a socket
varies depending on its address type; sockets with BSD addresses always
have UNIX_HASH_SIZE in their unix_sk(sk)->addr->hash.

This is just for the UNIX_ABSTRACT() macro used to check the address type.
The difference of the saved hashes comes from the first byte of the address
in the first place.  So, we can test it directly.

Then we can keep a real hash in each socket and replace unix_table_lock
with per-hash locks in the later patch.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:56 -08:00
Kuniyuki Iwashima
12f21c49ad af_unix: Allocate unix_address in unix_bind_(bsd|abstract)().
To terminate address with '\0' in unix_bind_bsd(), we add
unix_create_addr() and call it in unix_bind_bsd() and unix_bind_abstract().

Also, unix_bind_abstract() does not return -EEXIST.  Only
kern_path_create() and vfs_mknod() in unix_bind_bsd() can return it,
so we move the last error check in unix_bind() to unix_bind_bsd().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:56 -08:00
Kuniyuki Iwashima
5c32a3ed64 af_unix: Remove unix_mkname().
This patch removes unix_mkname() and postpones calculating a hash to
unix_bind_abstract().  Some BSD stuffs still remain in unix_bind()
though, the next patch packs them into unix_bind_bsd().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:55 -08:00
Kuniyuki Iwashima
d2d8c9fddb af_unix: Copy unix_mkname() into unix_find_(bsd|abstract)().
We should not call unix_mkname() before unix_find_other() and instead do
the same thing where necessary based on the address type:

  - terminating the address with '\0' in unix_find_bsd()
  - calculating the hash in unix_find_abstract().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:55 -08:00
Kuniyuki Iwashima
b8a58aa6fc af_unix: Cut unix_validate_addr() out of unix_mkname().
unix_mkname() tests socket address length and family and does some
processing based on the address type.  It is called in the early stage,
and therefore some instructions are redundant and can end up in vain.

The address length/family tests are done twice in unix_bind().  Also, the
address type is rechecked later in unix_bind() and unix_find_other(), where
we can do the same processing.  Moreover, in the BSD address case, the hash
is set to 0 but never used and confusing.

This patch moves the address tests out of unix_mkname(), and the following
patches move the other part into appropriate places and remove
unix_mkname() finally.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 18:01:55 -08:00