Commit Graph

793 Commits

Author SHA1 Message Date
David Howells
453a6d2a68 cifs: Fix oops due to uninitialised variable
Fix smb3_init_transform_rq() to initialise buffer to NULL before calling
netfs_alloc_folioq_buffer() as netfs assumes it can append to the buffer it
is given.  Setting it to NULL means it should start a fresh buffer, but the
value is currently undefined.

Fixes: a2906d3316 ("cifs: Switch crypto buffer to use a folio_queue rather than an xarray")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-19 11:16:14 -05:00
Wang Zhaolong
e19d8dd694 smb: client: remove redundant lstrp update in negotiate protocol
Commit 34331d7bee ("smb: client: fix first command failure during
re-negotiation") addressed a race condition by updating lstrp before
entering negotiate state. However, this approach may have some unintended
side effects.

The lstrp field is documented as "when we got last response from this
server", and updating it before actually receiving a server response
could potentially affect other mechanisms that rely on this timestamp.
For example, the SMB echo detection logic also uses lstrp as a reference
point. In scenarios with frequent user operations during reconnect states,
the repeated calls to cifs_negotiate_protocol() might continuously
update lstrp, which could interfere with the echo detection timing.

Additionally, commit 266b5d02e1 ("smb: client: fix race condition in
negotiate timeout by using more precise timing") introduced a dedicated
neg_start field specifically for tracking negotiate start time. This
provides a more precise solution for the original race condition while
preserving the intended semantics of lstrp.

Since the race condition is now properly handled by the neg_start
mechanism, the lstrp update in cifs_negotiate_protocol() is no longer
necessary and can be safely removed.

Fixes: 266b5d02e1 ("smb: client: fix race condition in negotiate timeout by using more precise timing")
Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-13 11:36:24 -05:00
Steve French
e3f776d30a cifs: update internal version number
to 2.56

Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-13 11:36:20 -05:00
Stefan Metzmacher
8c48e1c752 smb: client: don't wait for info->send_pending == 0 on error
We already called ib_drain_qp() before and that makes sure
send_done() was called with IB_WC_WR_FLUSH_ERR, but
didn't called atomic_dec_and_test(&sc->send_io.pending.count)

So we may never reach the info->send_pending == 0 condition.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: 5349ae5e05 ("smb: client: let send_done() cleanup before calling smbd_disconnect_rdma_connection()")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-13 11:36:12 -05:00
Wang Zhaolong
e3835731e1 smb: client: fix mid_q_entry memleak leak with per-mid locking
This is step 4/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.

In compound_send_recv(), when wait_for_response() is interrupted by
signals, the code attempts to cancel pending requests by changing
their callbacks to cifs_cancelled_callback. However, there's a race
condition between signal interruption and network response processing
that causes both mid_q_entry and server buffer leaks:

```
User foreground process                    cifsd
cifs_readdir
 open_cached_dir
  cifs_send_recv
   compound_send_recv
    smb2_setup_request
     smb2_mid_entry_alloc
      smb2_get_mid_entry
       smb2_mid_entry_alloc
        mempool_alloc // alloc mid
        kref_init(&temp->refcount); // refcount = 1
     mid[0]->callback = cifs_compound_callback;
     mid[1]->callback = cifs_compound_last_callback;
     smb_send_rqst
     rc = wait_for_response
      wait_event_state TASK_KILLABLE
                                  cifs_demultiplex_thread
                                    allocate_buffers
                                      server->bigbuf = cifs_buf_get()
                                    standard_receive3
                                      ->find_mid()
                                        smb2_find_mid
                                          __smb2_find_mid
                                           kref_get(&mid->refcount) // +1
                                      cifs_handle_standard
                                        handle_mid
                                         /* bigbuf will also leak */
                                         mid->resp_buf = server->bigbuf
                                         server->bigbuf = NULL;
                                         dequeue_mid
                                     /* in for loop */
                                    mids[0]->callback
                                      cifs_compound_callback
    /* Signal interrupts wait: rc = -ERESTARTSYS */
    /* if (... || midQ[i]->mid_state == MID_RESPONSE_RECEIVED) *?
    midQ[0]->callback = cifs_cancelled_callback;
    cancelled_mid[i] = true;
                                       /* The change comes too late */
                                       mid->mid_state = MID_RESPONSE_READY
                                    release_mid  // -1
    /* cancelled_mid[i] == true causes mid won't be released
       in compound_send_recv cleanup */
    /* cifs_cancelled_callback won't executed to release mid */
```

The root cause is that there's a race between callback assignment and
execution.

Fix this by introducing per-mid locking:

- Add spinlock_t mid_lock to struct mid_q_entry
- Add mid_execute_callback() for atomic callback execution
- Use mid_lock in cancellation paths to ensure atomicity

This ensures that either the original callback or the cancellation
callback executes atomically, preventing reference count leaks when
requests are interrupted by signals.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=220404
Fixes: ee258d7915 ("CIFS: Move credit processing to mid callbacks for SMB3")
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-13 11:36:05 -05:00
Steve French
7d34ec36ab smb3: fix for slab out of bounds on mount to ksmbd
With KASAN enabled, it is possible to get a slab out of bounds
during mount to ksmbd due to missing check in parse_server_interfaces()
(see below):

 BUG: KASAN: slab-out-of-bounds in
 parse_server_interfaces+0x14ee/0x1880 [cifs]
 Read of size 4 at addr ffff8881433dba98 by task mount/9827

 CPU: 5 UID: 0 PID: 9827 Comm: mount Tainted: G
 OE       6.16.0-rc2-kasan #2 PREEMPT(voluntary)
 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
 Hardware name: Dell Inc. Precision Tower 3620/0MWYPT,
 BIOS 2.13.1 06/14/2019
 Call Trace:
  <TASK>
 dump_stack_lvl+0x9f/0xf0
 print_report+0xd1/0x670
 __virt_addr_valid+0x22c/0x430
 ? parse_server_interfaces+0x14ee/0x1880 [cifs]
 ? kasan_complete_mode_report_info+0x2a/0x1f0
 ? parse_server_interfaces+0x14ee/0x1880 [cifs]
   kasan_report+0xd6/0x110
   parse_server_interfaces+0x14ee/0x1880 [cifs]
   __asan_report_load_n_noabort+0x13/0x20
   parse_server_interfaces+0x14ee/0x1880 [cifs]
 ? __pfx_parse_server_interfaces+0x10/0x10 [cifs]
 ? trace_hardirqs_on+0x51/0x60
 SMB3_request_interfaces+0x1ad/0x3f0 [cifs]
 ? __pfx_SMB3_request_interfaces+0x10/0x10 [cifs]
 ? SMB2_tcon+0x23c/0x15d0 [cifs]
 smb3_qfs_tcon+0x173/0x2b0 [cifs]
 ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
 ? cifs_get_tcon+0x105d/0x2120 [cifs]
 ? do_raw_spin_unlock+0x5d/0x200
 ? cifs_get_tcon+0x105d/0x2120 [cifs]
 ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
 cifs_mount_get_tcon+0x369/0xb90 [cifs]
 ? dfs_cache_find+0xe7/0x150 [cifs]
 dfs_mount_share+0x985/0x2970 [cifs]
 ? check_path.constprop.0+0x28/0x50
 ? save_trace+0x54/0x370
 ? __pfx_dfs_mount_share+0x10/0x10 [cifs]
 ? __lock_acquire+0xb82/0x2ba0
 ? __kasan_check_write+0x18/0x20
 cifs_mount+0xbc/0x9e0 [cifs]
 ? __pfx_cifs_mount+0x10/0x10 [cifs]
 ? do_raw_spin_unlock+0x5d/0x200
 ? cifs_setup_cifs_sb+0x29d/0x810 [cifs]
 cifs_smb3_do_mount+0x263/0x1990 [cifs]

Reported-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-13 11:36:02 -05:00
Dmitry Antipov
d7f1affc55 cifs: avoid extra calls to strlen() in cifs_get_spnego_key()
Since 'snprintf()' returns the number of characters emitted, an
output position may be advanced with this return value rather
than using an explicit calls to 'strlen()'. Compile tested only.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-11 23:20:26 -05:00
David Howells
b63335fb3d cifs: Fix collect_sample() to handle any iterator type
collect_sample() is used to gather samples of the data in a Write op for
analysis to try and determine if the compression algorithm is likely to
achieve anything more quickly than actually running the compression
algorithm.

However, collect_sample() assumes that the data it is going to be sampling
is stored in an ITER_XARRAY-type iterator (which it now should never be)
and doesn't actually check that it is before accessing the underlying
xarray directly.

Fix this by replacing the code with a loop that just uses the standard
iterator functions to sample every other 2KiB block, skipping the
intervening ones.  It's not quite the same as the previous algorithm as it
doesn't necessarily align to the pages within an ordinary write from the
pagecache.

Note that the btrfs code from which this was derived samples the inode's
pagecache directly rather than the iterator - but that doesn't necessarily
work for network filesystems if O_DIRECT is in operation.

Fixes: 94ae8c3fee ("smb: client: compress: LZ77 code improvements cleanup")
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: Enzo Matsumiya <ematsumiya@suse.de>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-11 23:20:07 -05:00
Paulo Alcantara
d84291fc74 smb: client: fix race with concurrent opens in rename(2)
Besides sending the rename request to the server, the rename process
also involves closing any deferred close, waiting for outstanding I/O
to complete as well as marking all existing open handles as deleted to
prevent them from deferring closes, which increases the race window
for potential concurrent opens on the target file.

Fix this by unhashing the dentry in advance to prevent any concurrent
opens on the target.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-10 12:39:51 -05:00
Paulo Alcantara
0af1561b2d smb: client: fix race with concurrent opens in unlink(2)
According to some logs reported by customers, CIFS client might end up
reporting unlinked files as existing in stat(2) due to concurrent
opens racing with unlink(2).

Besides sending the removal request to the server, the unlink process
could involve closing any deferred close as well as marking all
existing open handles as deleted to prevent them from deferring
closes, which increases the race window for potential concurrent
opens.

Fix this by unhashing the dentry in cifs_unlink() to prevent any
subsequent opens.  Any open attempts, while we're still unlinking,
will block on parent's i_rwsem.

Reported-by: Jay Shin <jaeshin@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-10 12:39:51 -05:00
Stefan Metzmacher
dfe6f14aed smb: client: only use a single wait_queue to monitor smbdirect connection status
There's no need for separate conn_wait and disconn_wait queues.

This will simplify the move to common code, the server code
already a single wait_queue for this.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-07 12:40:11 -05:00
Stefan Metzmacher
550a194c59 smb: client: don't call init_waitqueue_head(&info->conn_wait) twice in _smbd_get_connection
It is already called long before we may hit this cleanup code path.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-07 12:40:11 -05:00
Stefan Metzmacher
7613997457 smb: client: improve logging in smbd_conn_upcall()
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-07 12:40:11 -05:00
Stefan Metzmacher
03537826f7 smb: client: return an error if rdma_connect does not return within 5 seconds
This matches the timeout for tcp connections.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-07 12:40:11 -05:00
Stefan Metzmacher
bef82d5848 smb: client: make use of smbdirect_socket.{send,recv}_io.mem.{cache,pool}
This will allow common helper functions to be created later.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:18:58 -05:00
Stefan Metzmacher
977ea06fdd smb: client: make use of struct smbdirect_send_io
The server will also use this soon, so that we can
split out common helper functions in future.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:18:58 -05:00
Stefan Metzmacher
8b5964a118 smb: client: make use of SMBDIRECT_RECV_IO_MAX_SGE
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:18:58 -05:00
Stefan Metzmacher
b126645b79 smb: client: remove unused enum smbd_connection_status
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:18:58 -05:00
Stefan Metzmacher
61b4918e4e smb: client: make use of smbdirect_socket.recv_io.reassembly.*
This will be used by the server too and will allow us to
create common helper functions.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:14 -05:00
Stefan Metzmacher
5950045084 smb: client: make use of smb: smbdirect_socket.recv_io.free.{list,lock}
This will be used by the server too in order to have common
helper functions in future.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
5dddf04974 smb: client: make use of struct smbdirect_recv_io
This is the shared structure that will be used in
the server too and will allow us to move helper functions
into common code soon.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
bbdbd9ae47 smb: client: make use of smbdirect_socket->recv_io.expected
The expected incoming message type can be per connection.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
0edf9fc0a3 smb: client: remove unused smbd_connection->fragment_reassembly_remaining
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
24eff17887 smb: client: let recv_done() avoid touching data_transfer after cleanup/move
Calling enqueue_reassembly() and wake_up_interruptible(&info->wait_reassembly_queue)
or put_receive_buffer() means the response/data_transfer pointer might
get re-used by another thread, which means these should be
the last operations before calling return.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
bdd7afc6dc smb: client: let recv_done() cleanup before notifying the callers.
We should call put_receive_buffer() before waking up the callers.

For the internal error case of response->type being unexpected,
we now also call smbd_disconnect_rdma_connection() instead
of not waking up the callers at all.

Note that the SMBD_TRANSFER_DATA case still has problems,
which will be addressed in the next commit in order to make
it easier to review this one.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
047682c370 smb: client: make sure we call ib_dma_unmap_single() only if we called ib_dma_map_single already
In case of failures either ib_dma_map_single() might not be called yet
or ib_dma_unmap_single() was already called.

We should make sure put_receive_buffer() only calls
ib_dma_unmap_single() if needed.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
24b6afc36d smb: client: remove separate empty_packet_queue
There's no need to maintain two lists, we can just
have a single list of receive buffers, which are free to use.

It just added unneeded complexity and resulted in
ib_dma_unmap_single() not being called from recv_done()
for empty keepalive packets.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Stefan Metzmacher
5349ae5e05 smb: client: let send_done() cleanup before calling smbd_disconnect_rdma_connection()
We should call ib_dma_unmap_single() and mempool_free() before calling
smbd_disconnect_rdma_connection().

And smbd_disconnect_rdma_connection() needs to be the last function to
call as all other state might already be gone after it returns.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:13 -05:00
Yunseong Kim
b0b73329eb cifs: Fix null-ptr-deref by static initializing global lock
A kernel panic can be triggered by reading /proc/fs/cifs/debug_dirs.
The crash is a null-ptr-deref inside spin_lock(), caused by the use of the
uninitialized global spinlock cifs_tcp_ses_lock.

init_cifs()
 └── cifs_proc_init()
      └── // User can access /proc/fs/cifs/debug_dirs here
           └── cifs_debug_dirs_proc_show()
                └── spin_lock(&cifs_tcp_ses_lock); // Uninitialized!

KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000000] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in:
CPU: 3 UID: 0 PID: 16435 Comm: stress-ng-procf Not tainted 6.16.0-10385-g79f14b5d84c6 #37 PREEMPT
Hardware name: QEMU KVM Virtual Machine, BIOS 2025.02-8ubuntu1 06/11/2025
pstate: 23400005 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : do_raw_spin_lock+0x84/0x2cc
lr : _raw_spin_lock+0x24/0x34
sp : ffff8000966477e0
x29: ffff800096647860 x28: ffff800096647b88 x27: ffff0001c0c22070
x26: ffff0003eb2b60c8 x25: ffff0001c0c22018 x24: dfff800000000000
x23: ffff0000f624e000 x22: ffff0003eb2b6020 x21: ffff0000f624e768
x20: 0000000000000004 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff8000804b9600 x15: ffff700012cc8f04
x14: 1ffff00012cc8f04 x13: 0000000000000004 x12: ffffffffffffffff
x11: 1ffff00012cc8f00 x10: ffff80008d9af0d2 x9 : f3f3f304f1f1f1f1
x8 : 0000000000000000 x7 : 7365733c203e6469 x6 : 20656572743c2023
x5 : ffff0000e0ce0044 x4 : ffff80008a4deb6e x3 : ffff8000804b9718
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
do_raw_spin_lock+0x84/0x2cc (P)
_raw_spin_lock+0x24/0x34
cifs_debug_dirs_proc_show+0x1ac/0x4c0
seq_read_iter+0x3b0/0xc28
proc_reg_read_iter+0x178/0x2a8
vfs_read+0x5f8/0x88c
ksys_read+0x120/0x210
__arm64_sys_read+0x7c/0x90
invoke_syscall+0x98/0x2b8
el0_svc_common+0x130/0x23c
do_el0_svc+0x48/0x58
el0_svc+0x40/0x140
el0t_64_sync_handler+0x84/0x12c
el0t_64_sync+0x1ac/0x1b0
Code: aa0003f3 f9000feb f2fe7e69 f8386969 (38f86908)
---[ end trace 0000000000000000 ]---

The root cause is an initialization order problem. The lock is declared
as a global variable and intended to be initialized during module startup.
However, the procfs entry that uses this lock can be accessed by userspace
before the spin_lock_init() call has run. This creates a race window where
reading the proc file will attempt to use the lock before it is
initialized, leading to the crash.

For a global lock with a static lifetime, the correct and robust approach
is to use compile-time initialization.

Fixes: 844e5c0eb1 ("smb3 client: add way to show directory leases for improved debugging")
Signed-off-by: Yunseong Kim <ysk@kzalloc.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 15:04:00 -05:00
Steve French
1cdd5a2626 cifs: Move the SMB1 transport code out of transport.c
Shrink the size of cifs.ko when SMB1 is not enabled in the config
by moving the SMB1 transport code to different file.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-06 12:01:54 -05:00
Wang Zhaolong
3fd8ec2fc9 smb: client: smb: client: eliminate mid_flags field
This is step 3/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.

Replace the mid_flags bitmask with dedicated boolean fields to
simplify locking logic and improve code readability:

- Replace MID_DELETED with bool deleted_from_q
- Replace MID_WAIT_CANCELLED with bool wait_cancelled
- Remove mid_flags field entirely

The new boolean fields have clearer semantics:
- deleted_from_q: whether mid has been removed from pending_mid_q
- wait_cancelled: whether request was cancelled during wait

This change reduces memory usage (from 4-byte bitmask to 2 boolean
flags) and eliminates confusion about which lock protects which
flag bits, preparing for per-mid locking in the next patch.

Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-05 11:29:31 -05:00
Wang Zhaolong
9bd42798d5 smb: client: add mid_counter_lock to protect the mid counter counter
This is step 2/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.

Add a dedicated mid_counter_lock to protect current_mid counter,
separating it from mid_queue_lock which protects pending_mid_q
operations. This reduces lock contention and prepares for finer-
grained locking in subsequent patches.

Changes:
- Add TCP_Server_Info->mid_counter_lock spinlock
- Rename CurrentMid to current_mid for consistency
- Use mid_counter_lock to protect current_mid access
- Update locking documentation in cifsglob.h

This separation allows mid allocation to proceed without blocking
queue operations, improving performance under heavy load.

Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-05 11:29:00 -05:00
Wang Zhaolong
f3ba7c9b04 smb: client: rename server mid_lock to mid_queue_lock
This is step 1/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.

The current mid_lock name is somewhat ambiguous about what it protects.
To prepare for splitting this lock into separate, more granular locks,
this patch renames mid_lock to mid_queue_lock to clearly indicate its
specific responsibility for protecting the pending_mid_q list and
related queue operations.

No functional changes are made in this patch - it only prepares the
codebase for the lock splitting that follows.

- mid_queue_lock for queue operations
- mid_counter_lock for mid counter operations
- per-mid locks for individual mid state management

Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-05 11:25:48 -05:00
Paulo Alcantara
5b432ae5df smb: client: fix creating symlinks under POSIX mounts
SMB3.1.1 POSIX mounts support native symlinks that are created with
IO_REPARSE_TAG_SYMLINK reparse points, so skip the checking of
FILE_SUPPORTS_REPARSE_POINTS as some servers might not have it set.

Cc: linux-cifs@vger.kernel.org
Cc: Ralph Boehme <slow@samba.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Matthew Richardson <m.richardson@ed.ac.uk>
Closes: https://marc.info/?i=1124e7cd-6a46-40a6-9f44-b7664a66654b@ed.ac.uk
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-04 19:29:14 -05:00
Paulo Alcantara
6b445309ee smb: client: default to nonativesocket under POSIX mounts
SMB3.1.1 POSIX mounts require sockets to be created with NFS reparse
points.

Cc: linux-cifs@vger.kernel.org
Cc: Ralph Boehme <slow@samba.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Matthew Richardson <m.richardson@ed.ac.uk>
Closes: https://marc.info/?i=1124e7cd-6a46-40a6-9f44-b7664a66654b@ed.ac.uk
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-04 19:29:10 -05:00
Paulo Alcantara
a967e758f8 smb: client: set symlink type as native for POSIX mounts
SMB3.1.1 POSIX mounts require symlinks to be created natively with
IO_REPARSE_TAG_SYMLINK reparse point.

Cc: linux-cifs@vger.kernel.org
Cc: Ralph Boehme <slow@samba.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Matthew Richardson <m.richardson@ed.ac.uk>
Closes: https://marc.info/?i=1124e7cd-6a46-40a6-9f44-b7664a66654b@ed.ac.uk
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-01 00:16:19 -05:00
Linus Torvalds
db68e4c80d 16 smb3/cifs client fixes
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Merge tag 'v6.17-rc-part1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client updates from Steve French:

 - Fix network namespace refcount leak

 - Multichannel reconnect fix

 - Perf improvement to not do unneeded EA query on native symlinks

 - Performance improvement for directory leases to allow extending lease
   for actively queried directories

 - Improve debugging of directory leases by adding pseudofile to show
   them

 - Five minor mount cleanup patches

 - Minor directory lease cleanup patch

 - Allow creating special files via reparse points over SMB1

 - Two minor improvements to FindFirst over SMB1

 - Two NTLMSSP session setup fixes

* tag 'v6.17-rc-part1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3 client: add way to show directory leases for improved debugging
  smb: client: get rid of kstrdup() when parsing iocharset mount option
  smb: client: get rid of kstrdup() when parsing domain mount option
  smb: client: get rid of kstrdup() when parsing pass2 mount option
  smb: client: get rid of kstrdup() when parsing pass mount option
  smb: client: get rid of kstrdup() when parsing user mount option
  cifs: Add support for creating reparse points over SMB1
  cifs: Do not query WSL EAs for native SMB symlink
  cifs: Optimize CIFSFindFirst() response when not searching
  cifs: Fix calling CIFSFindFirst() for root path without msearch
  smb: client: fix session setup against servers that require SPN
  smb: client: allow parsing zero-length AV pairs
  cifs: add new field to track the last access time of cfid
  smb: change return type of cached_dir_lease_break() to bool
  cifs: reset iface weights when we cannot find a candidate
  smb: client: fix netns refcount leak after net_passive changes
2025-07-31 21:22:04 -07:00
Steve French
844e5c0eb1 smb3 client: add way to show directory leases for improved debugging
When looking at performance issues around directory caching, or debugging
directory lease issues, it is helpful to be able to display the current
directory leases (as we can e.g. or open files).  Create pseudo-file
/proc/fs/cifs/open_dirs that displays current directory leases.  Here
is sample output:

cat /proc/fs/cifs/open_dirs
 Version:1
 Format:
 <tree id> <sess id> <persistent fid> <path>
Num entries: 3
0xce4c1c68 0x7176aa54 0xd95ef58e     \dira      valid file info, valid dirents
0xce4c1c68 0x7176aa54 0xd031e211     \dir5      valid file info, valid dirents
0xce4c1c68 0x7176aa54 0x96533a90     \dir1      valid file info

Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-31 09:42:54 -05:00
Linus Torvalds
7031769e10 vfs-6.17-rc1.mmap_prepare
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Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull mmap_prepare updates from Christian Brauner:
 "Last cycle we introduce f_op->mmap_prepare() in c84bf6dd2b ("mm:
  introduce new .mmap_prepare() file callback").

  This is preferred to the existing f_op->mmap() hook as it does require
  a VMA to be established yet, thus allowing the mmap logic to invoke
  this hook far, far earlier, prior to inserting a VMA into the virtual
  address space, or performing any other heavy handed operations.

  This allows for much simpler unwinding on error, and for there to be a
  single attempt at merging a VMA rather than having to possibly
  reattempt a merge based on potentially altered VMA state.

  Far more importantly, it prevents inappropriate manipulation of
  incompletely initialised VMA state, which is something that has been
  the cause of bugs and complexity in the past.

  The intent is to gradually deprecate f_op->mmap, and in that vein this
  series coverts the majority of file systems to using f_op->mmap_prepare.

  Prerequisite steps are taken - firstly ensuring all checks for mmap
  capabilities use the file_has_valid_mmap_hooks() helper rather than
  directly checking for f_op->mmap (which is now not a valid check) and
  secondly updating daxdev_mapping_supported() to not require a VMA
  parameter to allow ext4 and xfs to be converted.

  Commit bb666b7c27 ("mm: add mmap_prepare() compatibility layer for
  nested file systems") handles the nasty edge-case of nested file
  systems like overlayfs, which introduces a compatibility shim to allow
  f_op->mmap_prepare() to be invoked from an f_op->mmap() callback.

  This allows for nested filesystems to continue to function correctly
  with all file systems regardless of which callback is used. Once we
  finally convert all file systems, this shim can be removed.

  As a result, ecryptfs, fuse, and overlayfs remain unaltered so they
  can nest all other file systems.

  We additionally do not update resctl - as this requires an update to
  remap_pfn_range() (or an alternative to it) which we defer to a later
  series, equally we do not update cramfs which needs a mixed mapping
  insertion with the same issue, nor do we update procfs, hugetlbfs,
  syfs or kernfs all of which require VMAs for internal state and hooks.
  We shall return to all of these later"

* tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  doc: update porting, vfs documentation to describe mmap_prepare()
  fs: replace mmap hook with .mmap_prepare for simple mappings
  fs: convert most other generic_file_*mmap() users to .mmap_prepare()
  fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()
  mm/filemap: introduce generic_file_*_mmap_prepare() helpers
  fs/xfs: transition from deprecated .mmap hook to .mmap_prepare
  fs/ext4: transition from deprecated .mmap hook to .mmap_prepare
  fs/dax: make it possible to check dev dax support without a VMA
  fs: consistently use can_mmap_file() helper
  mm/nommu: use file_has_valid_mmap_hooks() helper
  mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare
2025-07-28 13:43:25 -07:00
Linus Torvalds
11fe69fbd5 Current exclusion rules for ->d_flags stores are rather unpleasant.
The basic rules are simple:
 	* stores to dentry->d_flags are OK under dentry->d_lock.
 	* stores to dentry->d_flags are OK in the dentry constructor, before
 becomes potentially visible to other threads.
 Unfortunately, there's a couple of exceptions to that, and that's where the
 headache comes from.
 
 	Main PITA comes from d_set_d_op(); that primitive sets ->d_op
 of dentry and adjusts the flags that correspond to presence of individual
 methods.  It's very easy to misuse; existing uses _are_ safe, but proof
 of correctness is brittle.
 
 	Use in __d_alloc() is safe (we are within a constructor), but we
 might as well precalculate the initial value of ->d_flags when we set
 the default ->d_op for given superblock and set ->d_flags directly
 instead of messing with that helper.
 
 	The reasons why other uses are safe are bloody convoluted; I'm not going
 to reproduce it here.  See https://lore.kernel.org/all/20250224010624.GT1977892@ZenIV/
 for gory details, if you care.  The critical part is using d_set_d_op() only
 just prior to d_splice_alias(), which makes a combination of d_splice_alias()
 with setting ->d_op, etc. a natural replacement primitive.  Better yet, if
 we go that way, it's easy to take setting ->d_op and modifying ->d_flags
 under ->d_lock, which eliminates the headache as far as ->d_flags exclusion
 rules are concerned.  Other exceptions are minor and easy to deal with.
 
 	What this series does:
 * d_set_d_op() is no longer available; new primitive (d_splice_alias_ops())
 is provided, equivalent to combination of d_set_d_op() and d_splice_alias().
 * new field of struct super_block - ->s_d_flags.  Default value of ->d_flags
 to be used when allocating dentries on this filesystem.
 * new primitive for setting ->s_d_op: set_default_d_op().  Replaces stores
 to ->s_d_op at mount time.  All in-tree filesystems converted; out-of-tree
 ones will get caught by compiler (->s_d_op is renamed, so stores to it will
 be caught).  ->s_d_flags is set by the same primitive to match the ->s_d_op.
 * a lot of filesystems had ->s_d_op->d_delete equal to always_delete_dentry;
 that is equivalent to setting DCACHE_DONTCACHE in ->d_flags, so such filesystems
 can bloody well set that bit in ->s_d_flags and drop ->d_delete() from
 dentry_operations.  In quite a few cases that results in empty dentry_operations,
 which means that we can get rid of those.
 * kill simple_dentry_operations - not needed anymore.
 * massage d_alloc_parallel() to get rid of the other exception wrt ->d_flags
 stores - we can set DCACHE_PAR_LOOKUP as soon as we allocate the new dentry;
 no need to delay that until we commit to using the sucker.
 
 As the result, ->d_flags stores are all either under ->d_lock or done before
 the dentry becomes visible in any shared data structures.
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Merge tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull dentry d_flags updates from Al Viro:
 "The current exclusion rules for dentry->d_flags stores are rather
  unpleasant. The basic rules are simple:

   - stores to dentry->d_flags are OK under dentry->d_lock

   - stores to dentry->d_flags are OK in the dentry constructor, before
     becomes potentially visible to other threads

  Unfortunately, there's a couple of exceptions to that, and that's
  where the headache comes from.

  The main PITA comes from d_set_d_op(); that primitive sets ->d_op of
  dentry and adjusts the flags that correspond to presence of individual
  methods. It's very easy to misuse; existing uses _are_ safe, but proof
  of correctness is brittle.

  Use in __d_alloc() is safe (we are within a constructor), but we might
  as well precalculate the initial value of 'd_flags' when we set the
  default ->d_op for given superblock and set 'd_flags' directly instead
  of messing with that helper.

  The reasons why other uses are safe are bloody convoluted; I'm not
  going to reproduce it here. See [1] for gory details, if you care. The
  critical part is using d_set_d_op() only just prior to
  d_splice_alias(), which makes a combination of d_splice_alias() with
  setting ->d_op, etc a natural replacement primitive.

  Better yet, if we go that way, it's easy to take setting ->d_op and
  modifying 'd_flags' under ->d_lock, which eliminates the headache as
  far as 'd_flags' exclusion rules are concerned. Other exceptions are
  minor and easy to deal with.

  What this series does:

   - d_set_d_op() is no longer available; instead a new primitive
     (d_splice_alias_ops()) is provided, equivalent to combination of
     d_set_d_op() and d_splice_alias().

   - new field of struct super_block - 's_d_flags'. This sets the
     default value of 'd_flags' to be used when allocating dentries on
     this filesystem.

   - new primitive for setting 's_d_op': set_default_d_op(). This
     replaces stores to 's_d_op' at mount time.

     All in-tree filesystems converted; out-of-tree ones will get caught
     by the compiler ('s_d_op' is renamed, so stores to it will be
     caught). 's_d_flags' is set by the same primitive to match the
     's_d_op'.

   - a lot of filesystems had sb->s_d_op->d_delete equal to
     always_delete_dentry; that is equivalent to setting
     DCACHE_DONTCACHE in 'd_flags', so such filesystems can bloody well
     set that bit in 's_d_flags' and drop 'd_delete()' from
     dentry_operations.

     In quite a few cases that results in empty dentry_operations, which
     means that we can get rid of those.

   - kill simple_dentry_operations - not needed anymore

   - massage d_alloc_parallel() to get rid of the other exception wrt
     'd_flags' stores - we can set DCACHE_PAR_LOOKUP as soon as we
     allocate the new dentry; no need to delay that until we commit to
     using the sucker.

  As the result, 'd_flags' stores are all either under ->d_lock or done
  before the dentry becomes visible in any shared data structures"

Link: https://lore.kernel.org/all/20250224010624.GT1977892@ZenIV/ [1]

* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (21 commits)
  configfs: use DCACHE_DONTCACHE
  debugfs: use DCACHE_DONTCACHE
  efivarfs: use DCACHE_DONTCACHE instead of always_delete_dentry()
  9p: don't bother with always_delete_dentry
  ramfs, hugetlbfs, mqueue: set DCACHE_DONTCACHE
  kill simple_dentry_operations
  devpts, sunrpc, hostfs: don't bother with ->d_op
  shmem: no dentry retention past the refcount reaching zero
  d_alloc_parallel(): set DCACHE_PAR_LOOKUP earlier
  make d_set_d_op() static
  simple_lookup(): just set DCACHE_DONTCACHE
  tracefs: Add d_delete to remove negative dentries
  set_default_d_op(): calculate the matching value for ->d_flags
  correct the set of flags forbidden at d_set_d_op() time
  split d_flags calculation out of d_set_d_op()
  new helper: set_default_d_op()
  fuse: no need for special dentry_operations for root dentry
  switch procfs from d_set_d_op() to d_splice_alias_ops()
  new helper: d_splice_alias_ops()
  procfs: kill ->proc_dops
  ...
2025-07-28 09:17:57 -07:00
Paulo Alcantara
28f09823de smb: client: get rid of kstrdup() when parsing iocharset mount option
Steal string reference from @param->string rather than duplicating it.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-28 09:42:53 -05:00
Paulo Alcantara
60c9511253 smb: client: get rid of kstrdup() when parsing domain mount option
Steal string reference from @param->string rather than duplicating it.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-28 09:42:05 -05:00
Paulo Alcantara
1b6075ebd3 smb: client: get rid of kstrdup() when parsing pass2 mount option
Steal string reference from @param->string rather than duplicating it.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-28 09:41:17 -05:00
Paulo Alcantara
524fa5bcc3 smb: client: get rid of kstrdup() when parsing pass mount option
Steal string reference from @param->string rather than duplicating it.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-28 09:40:36 -05:00
Paulo Alcantara
e5acab35fe smb: client: get rid of kstrdup() when parsing user mount option
Steal string reference from @param->string rather than duplicating it.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-28 09:40:20 -05:00
Pali Rohár
309c2b776c cifs: Add support for creating reparse points over SMB1
SMB1 already supports querying reparse points and detecting types of
symlink, fifo, socket, block and char.

This change implements the missing part - ability to create a new reparse
points over SMB1. This includes everything which SMB2+ already supports:
- native SMB symlinks and sockets
- NFS style of special files (symlinks, fifos, sockets, char/block devs)
- WSL style of special files (symlinks, fifos, sockets, char/block devs)

Attaching a reparse point to an existing file or directory is done via
SMB1 SMB_COM_NT_TRANSACT/NT_TRANSACT_IOCTL/FSCTL_SET_REPARSE_POINT command
and implemented in a new cifs_create_reparse_inode() function.

This change introduce a new callback ->create_reparse_inode() which creates
a new reperse point file or directory and returns inode. For SMB1 it is
provided via that new cifs_create_reparse_inode() function.

Existing reparse.c code was only slightly updated to call new protocol
callback ->create_reparse_inode() instead of hardcoded SMB2+ function.
This make the whole reparse.c code to work with every SMB dialect.

The original callback ->create_reparse_symlink() is not needed anymore as
the implementation of new create_reparse_symlink() function is dialect
agnostic too. So the link.c code was updated to call that function directly
(and not via callback).

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-27 17:43:08 -05:00
Pali Rohár
75d519b0b5 cifs: Do not query WSL EAs for native SMB symlink
WSL EAs are not required for native SMB symlinks, so do not query them from server.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-27 16:59:59 -05:00
Pali Rohár
b62a206bfb cifs: Optimize CIFSFindFirst() response when not searching
When not searching for child entries with msearch wildcard pattern then ask
server just for one output entry. There is no need to ask for more entries
as we are interested only for one search result, as we are doing query on
path.

CIFSFindFirst() with msearch=false is called by the cifs_query_path_info()
function.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-27 16:59:59 -05:00
Pali Rohár
b460249b9a cifs: Fix calling CIFSFindFirst() for root path without msearch
To query root path (without msearch wildcard) it is needed to
send pattern '\' instead of '' (empty string).

This allows to use CIFSFindFirst() to query information about root path
which is being used in followup changes.

This change fixes the stat() syscall called on the root path on the mount.
It is because stat() syscall uses the cifs_query_path_info() function and
it can fallback to the CIFSFindFirst() usage with msearch=false.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-27 16:59:59 -05:00
Paulo Alcantara
33cfdd7263 smb: client: fix session setup against servers that require SPN
Some servers might enforce the SPN to be set in the target info
blob (AV pairs) when sending NTLMSSP_AUTH message.  In Windows Server,
this could be enforced with SmbServerNameHardeningLevel set to 2.

Fix this by always appending SPN (cifs/<hostname>) to the existing
list of target infos when setting up NTLMv2 response blob.

Cc: linux-cifs@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Reported-by: Pierguido Lambri <plambri@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-27 16:59:59 -05:00