Commit Graph

46 Commits

Author SHA1 Message Date
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
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
Paulo Alcantara
3363da82e0 smb: client: fix native SMB symlink traversal
We've seen customers having shares mounted in paths like /??/C:/ or
/??/UNC/foo.example.com/share in order to get their native SMB
symlinks successfully followed from different mounts.

After commit 12b466eb52 ("cifs: Fix creating and resolving absolute NT-style symlinks"),
the client would then convert absolute paths from "/??/C:/" to "/mnt/c/"
by default.  The absolute paths would vary depending on the value of
symlinkroot= mount option.

Fix this by restoring old behavior of not trying to convert absolute
paths by default.  Only do this if symlinkroot= was _explicitly_ set.

Before patch:

  $ mount.cifs //w22-fs0/test2 /mnt/1 -o vers=3.1.1,username=xxx,password=yyy
  $ ls -l /mnt/1/symlink2
  lrwxr-xr-x 1 root root 15 Jun 20 14:22 /mnt/1/symlink2 -> /mnt/c/testfile
  $ mkdir -p /??/C:; echo foo > //??/C:/testfile
  $ cat /mnt/1/symlink2
  cat: /mnt/1/symlink2: No such file or directory

After patch:

  $ mount.cifs //w22-fs0/test2 /mnt/1 -o vers=3.1.1,username=xxx,password=yyy
  $ ls -l /mnt/1/symlink2
  lrwxr-xr-x 1 root root 15 Jun 20 14:22 /mnt/1/symlink2 -> '/??/C:/testfile'
  $ mkdir -p /??/C:; echo foo > //??/C:/testfile
  $ cat /mnt/1/symlink2
  foo

Cc: linux-cifs@vger.kernel.org
Reported-by: Pierguido Lambri <plambri@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Stefan Metzmacher <metze@samba.org>
Fixes: 12b466eb52 ("cifs: Fix creating and resolving absolute NT-style symlinks")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-07-03 18:43:04 -05:00
Paulo Alcantara
c59f7c9661 smb: client: ensure aligned IO sizes
Make all IO sizes multiple of PAGE_SIZE, either negotiated by the
server or passed through rsize, wsize and bsize mount options, to
prevent from breaking DIO reads and writes against servers that
enforce alignment as specified in MS-FSA 2.1.5.3 and 2.1.5.4.

Cc: linux-cifs@vger.kernel.org
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-05-01 08:35:58 -05:00
Pali Rohár
7d14dd683b cifs: Allow to disable or force initialization of NetBIOS session
Currently SMB client always tries to initialize NetBIOS session when the
server port is 139. This is useful for default cases, but nowadays when
using non-standard routing or testing between VMs, it is common that
servers are listening on non-standard ports.

So add a new mount option -o nbsessinit and -o nonbsessinit which either
forces initialization or disables initialization regardless of server port
number.

This allows Linux SMB client to connect to older SMB1 server listening on
non-standard port, which requires initialization of NetBIOS session, by
using additional mount options -o port= and -o nbsessinit.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-04-01 01:54:17 -05:00
Wang Zhaolong
287906b200 smb: client: Store original IO parameters and prevent zero IO sizes
During mount option processing and negotiation with the server, the
original user-specified rsize/wsize values were being modified directly.
This makes it impossible to recover these values after a connection
reset, leading to potential degraded performance after reconnection.

The other problem is that When negotiating read and write sizes, there are
cases where the negotiated values might calculate to zero, especially
during reconnection when server->max_read or server->max_write might be
reset. In general, these values come from the negotiation response.
According to MS-SMB2 specification, these values should be at least 65536
bytes.

This patch improves IO parameter handling:

1. Adds vol_rsize and vol_wsize fields to store the original user-specified
   values separately from the negotiated values
2. Uses got_rsize/got_wsize flags to determine if values were
   user-specified rather than checking for non-zero values, which is more
   reliable
3. Adds a prevent_zero_iosize() helper function to ensure IO sizes are
   never negotiated down to zero, which could happen in edge cases like
   when server->max_read/write is zero

The changes make the CIFS client more resilient to unusual server
responses and reconnection scenarios, preventing potential failures
when IO sizes are calculated to be zero.

Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-31 21:12:31 -05:00
Roman Smirnov
2510859475 cifs: fix integer overflow in match_server()
The echo_interval is not limited in any way during mounting,
which makes it possible to write a large number to it. This can
cause an overflow when multiplying ctx->echo_interval by HZ in
match_server().

Add constraints for echo_interval to smb3_fs_context_parse_param().

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: adfeb3e00e ("cifs: Make echo interval tunable")
Cc: stable@vger.kernel.org
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-31 21:10:17 -05:00
Pali Rohár
e14b642474 cifs: Add new mount option -o nounicode to disable SMB1 UNICODE mode
SMB1 protocol supports non-UNICODE (8-bit OEM character set) and
UNICODE (UTF-16) modes.

Linux SMB1 client implements both of them but currently does not allow to
choose non-UNICODE mode when SMB1 server announce UNICODE mode support.

This change adds a new mount option -o nounicode to disable UNICODE mode
and force usage of non-UNICODE (8-bit OEM character set) mode.

This allows to test non-UNICODE implementation of Linux SMB1 client against
any SMB1 server, including modern and recent Windows SMB1 server.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-26 14:51:58 -05:00
Pali Rohár
be786e509c cifs: Set default Netbios RFC1001 server name to hostname in UNC
Windows SMB servers (including SMB2+) which are working over RFC1001
require that Netbios server name specified in RFC1001 Session Request
packet is same as the UNC host name. Netbios server name can be already
specified manually via -o servern= option.

With this change the RFC1001 server name is set automatically by extracting
the hostname from the mount source.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-26 14:51:50 -05:00
Murad Masimov
d5a30fddfe cifs: Fix integer overflow while processing closetimeo mount option
User-provided mount parameter closetimeo of type u32 is intended to have
an upper limit, but before it is validated, the value is converted from
seconds to jiffies which can lead to an integer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 5efdd9122e ("smb3: allow deferred close timeout to be configurable")
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13 08:41:28 -05:00
Murad Masimov
64f690ee22 cifs: Fix integer overflow while processing actimeo mount option
User-provided mount parameter actimeo of type u32 is intended to have
an upper limit, but before it is validated, the value is converted from
seconds to jiffies which can lead to an integer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 6d20e8406f ("cifs: add attribute cache timeout (actimeo) tunable")
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13 08:41:28 -05:00
Murad Masimov
5b29891f91 cifs: Fix integer overflow while processing acdirmax mount option
User-provided mount parameter acdirmax of type u32 is intended to have
an upper limit, but before it is validated, the value is converted from
seconds to jiffies which can lead to an integer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 4c9f948142 ("cifs: Add new mount parameter "acdirmax" to allow caching directory metadata")
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13 08:41:27 -05:00
Murad Masimov
7489161b18 cifs: Fix integer overflow while processing acregmax mount option
User-provided mount parameter acregmax of type u32 is intended to have
an upper limit, but before it is validated, the value is converted from
seconds to jiffies which can lead to an integer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 5780464614 ("cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout")
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13 08:41:27 -05:00
Paulo Alcantara
fc99045eff smb: client: fix regression with guest option
When mounting a CIFS share with 'guest' mount option, mount.cifs(8)
will set empty password= and password2= options.  Currently we only
handle empty strings from user= and password= options, so the mount
will fail with

	cifs: Bad value for 'password2'

Fix this by handling empty string from password2= option as well.

Link: https://bbs.archlinux.org/viewtopic.php?id=303927
Reported-by: Adam Williamson <awilliam@redhat.com>
Closes: https://lore.kernel.org/r/83c00b5fea81c07f6897a5dd3ef50fd3b290f56c.camel@redhat.com
Fixes: 35f834265e ("smb3: fix broken reconnect when password changing on the server by allowing password rotation")
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13 08:40:24 -05:00
Pali Rohár
45a99d5d11 cifs: Add support for creating native Windows sockets
Native Windows sockets created by WinSock on Windows 10 April 2018 Update
(version 1803) or Windows Server 2019 (version 1809) or later versions is
reparse point with IO_REPARSE_TAG_AF_UNIX tag, with empty reparse point
data buffer and without any EAs.

Create AF_UNIX sockets in this native format if -o nonativesocket was not
specified.

This change makes AF_UNIX sockets created by Linux CIFS client compatible
with AF_UNIX sockets created by Windows applications on NTFS volumes.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31 12:51:20 -06:00
Pali Rohár
78f69467cb cifs: Add mount option -o reparse=none
This new mount option allows to completely disable creating new reparse
points. When -o sfu or -o mfsymlinks or -o symlink= is not specified then
creating any special file (fifo, socket, symlink, block and char) will fail
with -EOPNOTSUPP error.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29 17:35:38 -06:00
Pali Rohár
660618dde2 cifs: Add mount option -o symlink= for choosing symlink create type
Currently Linux CIFS client creates a new symlink of the first flavor which
is allowed by mount options, parsed in this order: -o (no)mfsymlinks,
-o (no)sfu, -o (no)unix (+ its aliases) and -o reparse=[type].

Introduce a new mount option -o symlink= for explicitly choosing a symlink
flavor. Possible options are:

  -o symlink=default    - The default behavior, like before this change.
  -o symlink=none       - Disallow creating a new symlinks
  -o symlink=native     - Create as native SMB symlink reparse point
  -o symlink=unix       - Create via SMB1 unix extension command
  -o symlink=mfsymlinks - Create as regular file of mfsymlinks format
  -o symlink=sfu        - Create as regular system file of SFU format
  -o symlink=nfs        - Create as NFS reparse point
  -o symlink=wsl        - Create as WSL reparse point

So for example specifying -o sfu,mfsymlinks,symlink=native will allow to
parse symlinks also of SFU and mfsymlinks types (which are disabled by
default unless mount option is explicitly specified), but new symlinks will
be created under native SMB type (which parsing is always enabled).

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29 17:35:32 -06:00
Pali Rohár
12b466eb52 cifs: Fix creating and resolving absolute NT-style symlinks
If the SMB symlink is stored on NT server in absolute form then it points
to the NT object hierarchy, which is different from POSIX one and needs
some conversion / mapping.

To make interoperability with Windows SMB server and WSL subsystem, reuse
its logic of mapping between NT paths and POSIX paths into Linux SMB
client.

WSL subsystem on Windows uses for -t drvfs mount option -o symlinkroot=
which specifies the POSIX path where are expected to be mounted lowercase
Windows drive letters (without colon).

Do same for Linux SMB client and add a new mount option -o symlinkroot=
which mimics the drvfs mount option of the same name. It specifies where in
the Linux VFS hierarchy is the root of the DOS / Windows drive letters, and
translates between absolute NT-style symlinks and absolute Linux VFS
symlinks. Default value of symlinkroot is "/mnt", same what is using WSL.

Note that DOS / Windows drive letter symlinks are just subset of all
possible NT-style symlinks. Drive letters live in NT subtree \??\ and
important details about NT paths and object hierarchy are in the comments
in this change.

When symlink target location from non-POSIX SMB server is in absolute form
(indicated by absence of SYMLINK_FLAG_RELATIVE) then it is converted to
Linux absolute symlink according to symlinkroot configuration.

And when creating a new symlink on non-POSIX SMB server in absolute form
then Linux absolute target is converted to NT-style according to
symlinkroot configuration.

When SMB server is POSIX, then this change does not affect neither reading
target location of symlink, nor creating a new symlink. It is expected that
POSIX SMB server works with POSIX paths where the absolute root is /.

This change improves interoperability of absolute SMB symlinks with Windows
SMB servers.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29 17:35:06 -06:00
Paulo Alcantara
ad46faff1a smb: client: fix DFS mount against old servers with NTLMSSP
Old Windows servers will return not fully qualified DFS targets by
default as specified in

  MS-DFSC 3.2.5.5 Receiving a Root Referral Request or Link Referral
  Request

    | Servers SHOULD<30> return fully qualified DNS host names of
    | targets in responses to root referral requests and link referral
    | requests.
    | ...
    | <30> Section 3.2.5.5: By default, Windows Server 2003, Windows
    | Server 2008, Windows Server 2008 R2, Windows Server 2012, and
    | Windows Server 2012 R2 return DNS host names that are not fully
    | qualified for targets.

Fix this by converting all NetBIOS host names from DFS targets to
FQDNs and try resolving them first if DNS domain name was provided in
NTLMSSP CHALLENGE_MESSAGE message from previous SMB2_SESSION_SETUP.
This also prevents the client from translating the DFS target
hostnames to another domain depending on the network domain search
order.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-19 19:34:00 -06:00
Dan Carpenter
cda88d2fef cifs: unlock on error in smb3_reconfigure()
Unlock before returning if smb3_sync_session_ctx_passwords() fails.

Fixes: 7e654ab7da03 ("cifs: during remount, make sure passwords are in sync")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-28 09:51:11 -06:00
Shyam Prasad N
0f0e357902 cifs: during remount, make sure passwords are in sync
This fixes scenarios where remount can overwrite the only currently
working password, breaking reconnect.

We recently introduced a password2 field in both ses and ctx structs.
This was done so as to allow the client to rotate passwords for a mount
without any downtime. However, when the client transparently handles
password rotation, it can swap the values of the two password fields
in the ses struct, but not in smb3_fs_context struct that hangs off
cifs_sb. This can lead to a situation where a remount unintentionally
overwrites a working password in the ses struct.

In order to fix this, we first get the passwords in ctx struct
in-sync with ses struct, before replacing them with what the passwords
that could be passed as a part of remount.

Also, in order to avoid race condition between smb2_reconnect and
smb3_reconfigure, we make sure to lock session_mutex before changing
password and password2 fields of the ses structure.

Fixes: 35f834265e ("smb3: fix broken reconnect when password changing on the server by allowing password rotation")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-28 09:51:07 -06:00
Ritvik Budhiraja
db363b0a1d CIFS: New mount option for cifs.upcall namespace resolution
In the current implementation, the SMB filesystem on a mount point can
trigger upcalls from the kernel to the userspace to enable certain
functionalities like spnego, dns_resolution, amongst others. These upcalls
usually either happen in the context of the mount or in the context of an
application/user. The upcall handler for cifs, cifs.upcall already has
existing code which switches the namespaces to the caller's namespace
before handling the upcall. This behaviour is expected for scenarios like
multiuser mounts, but might not cover all single user scenario with
services such as Kubernetes, where the mount can happen from different
locations such as on the host, from an app container, or a driver pod
which does the mount on behalf of a different pod.

This patch introduces a new mount option called upcall_target, to
customise the upcall behaviour. upcall_target can take 'mount' and 'app'
as possible values. This aids use cases like Kubernetes where the mount
happens on behalf of the application in another container altogether.
Having this new mount option allows the mount command to specify where the
upcall should happen: 'mount' for resolving the upcall to the host
namespace, and 'app' for resolving the upcall to the ns of the calling
thread. This will enable both the scenarios where the Kerberos credentials
can be found on the application namespace or the host namespace to which
just the mount operation is "delegated".

Reviewed-by: Shyam Prasad <shyam.prasad@microsoft.com>
Reviewed-by: Bharath S M <bharathsm@microsoft.com>
Reviewed-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-21 10:44:03 -06:00
Henrique Carvalho
9a5dd61151 smb: client: Handle kstrdup failures for passwords
In smb3_reconfigure(), after duplicating ctx->password and
ctx->password2 with kstrdup(), we need to check for allocation
failures.

If ses->password allocation fails, return -ENOMEM.
If ses->password2 allocation fails, free ses->password, set it
to NULL, and return -ENOMEM.

Fixes: c1eb537bf4 ("cifs: allow changing password during remount")
Reviewed-by: David Howells <dhowells@redhat.com
Signed-off-by: Haoxiang Li <make24@iscas.ac.cn>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-10-23 07:42:22 -05:00
Pali Rohár
41d3f256c6 cifs: Add support for creating SFU symlinks
Linux cifs client can already detect SFU symlinks and reads it content
(target location). But currently is not able to create new symlink. So
implement this missing support.

When 'sfu' mount option is specified and 'mfsymlinks' is not specified then
create new symlinks in SFU-style. This will provide full SFU compatibility
of symlinks when mounting cifs share with 'sfu' option. 'mfsymlinks' option
override SFU for better Apple compatibility as explained in fs_context.c
file in smb3_update_mnt_flags() function.

Extend __cifs_sfu_make_node() function, which now can handle also S_IFLNK
type and refactor structures passed to sync_write() in this function, by
splitting SFU type and SFU data from original combined struct win_dev as
combined fixed-length struct cannot be used for variable-length symlinks.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-09-16 20:10:34 -05:00
Steve French
d14bbfff25 smb3: mark compression as CONFIG_EXPERIMENTAL and fix missing compression operation
Move SMB3.1.1 compression code into experimental config option,
and fix the compress mount option. Implement unchained LZ77
"plain" compression algorithm as per MS-XCA specification
section "2.3 Plain LZ77 Compression Algorithm Details".

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-09-15 10:42:44 -05:00
Eric Sandeen
3229e3a5a3
smb: client: Convert to new uid/gid option parsing helpers
Convert to new uid/gid option parsing helpers

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Link: https://lore.kernel.org/r/2543358a-b97e-45ce-8cdc-3de1dd9a782f@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-02 06:21:20 +02:00
Takayuki Nagata
77d8aa79ec cifs: reinstate original behavior again for forceuid/forcegid
forceuid/forcegid should be enabled by default when uid=/gid= options are
specified, but commit 24e0a1eff9 ("cifs: switch to new mount api")
changed the behavior. Due to the change, a mounted share does not show
intentional uid/gid for files and directories even though uid=/gid=
options are specified since forceuid/forcegid are not enabled.

This patch reinstates original behavior that overrides uid/gid with
specified uid/gid by the options.

Fixes: 24e0a1eff9 ("cifs: switch to new mount api")
Signed-off-by: Takayuki Nagata <tnagata@redhat.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-22 10:50:31 -05:00
Steve French
35f834265e smb3: fix broken reconnect when password changing on the server by allowing password rotation
There are various use cases that are becoming more common in which password
changes are scheduled on a server(s) periodically but the clients connected
to this server need to stay connected (even in the face of brief network
reconnects) due to mounts which can not be easily unmounted and mounted at
will, and servers that do password rotation do not always have the ability
to tell the clients exactly when to the new password will be effective,
so add support for an alt password ("password2=") on mount (and also
remount) so that we can anticipate the upcoming change to the server
without risking breaking existing mounts.

An alternative would have been to use the kernel keyring for this but the
processes doing the reconnect do not have access to the keyring but do
have access to the ses structure.

Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-11 16:03:48 -05:00
Paulo Alcantara
93cee45ccf smb: client: serialise cifs_construct_tcon() with cifs_mount_mutex
Serialise cifs_construct_tcon() with cifs_mount_mutex to handle
parallel mounts that may end up reusing the session and tcon created
by it.

Cc: stable@vger.kernel.org # 6.4+
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-02 10:12:22 -05:00
Enzo Matsumiya
8fe7062b7d smb: client: negotiate compression algorithms
Change "compress=" mount option to a boolean flag, that, if set,
will enable negotiating compression algorithms with the server.

Do not de/compress anything for now.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:52:42 -05:00
Paulo Alcantara
5a4b09ecf8 smb: client: add support for WSL reparse points
Add support for creating special files via WSL reparse points when
using 'reparse=wsl' mount option.  They're faster than NFS reparse
points because they don't require extra roundtrips to figure out what
->d_type a specific dirent is as such information is already stored in
query dir responses and then making getdents() calls faster.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:33:58 -05:00
Paulo Alcantara
eb90e8ecb2 smb: client: introduce reparse mount option
Allow the user to create special files and symlinks by choosing
between WSL and NFS reparse points via 'reparse={nfs,wsl}' mount
options.  If unset or 'reparse=default', the client will default to
creating them via NFS reparse points.

Creating WSL reparse points isn't supported yet, so simply return
error when attempting to mount with 'reparse=wsl' for now.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:33:54 -05:00
Steve French
c1eb537bf4 cifs: allow changing password during remount
There are cases where a session is disconnected and password has changed
on the server (or expired) for this user and this currently can not
be fixed without unmount and mounting again.  This patch allows
remount to change the password (for the non Kerberos case, Kerberos
ticket refresh is handled differently) when the session is disconnected
and the user can not reconnect due to still using old password.

Future patches should also allow us to setup the keyring (cifscreds)
to have an "alternate password" so we would be able to change
the password before the session drops (without the risk of races
between when the password changes and the disconnect occurs -
ie cases where the old password is still needed because the new
password has not fully rolled out to all servers yet).

Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:33:53 -05:00
Steve French
4860abb91f smb: Fix regression in writes when non-standard maximum write size negotiated
The conversion to netfs in the 6.3 kernel caused a regression when
maximum write size is set by the server to an unexpected value which is
not a multiple of 4096 (similarly if the user overrides the maximum
write size by setting mount parm "wsize", but sets it to a value that
is not a multiple of 4096).  When negotiated write size is not a
multiple of 4096 the netfs code can skip the end of the final
page when doing large sequential writes, causing data corruption.

This section of code is being rewritten/removed due to a large
netfs change, but until that point (ie for the 6.3 kernel until now)
we can not support non-standard maximum write sizes.

Add a warning if a user specifies a wsize on mount that is not
a multiple of 4096 (and round down), also add a change where we
round down the maximum write size if the server negotiates a value
that is not a multiple of 4096 (we also have to check to make sure that
we do not round it down to zero).

Reported-by: R. Diez" <rdiez-2006@rd10.de>
Fixes: d08089f649 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Suggested-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Acked-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org # v6.3+
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-15 22:19:23 -06:00
Steve French
a5cc98eba2 smb3: clarify mount warning
When a user tries to use the "sec=krb5p" mount parameter to encrypt
data on connection to a server (when authenticating with Kerberos), we
indicate that it is not supported, but do not note the equivalent
recommended mount parameter ("sec=krb5,seal") which turns on encryption
for that mount (and uses Kerberos for auth).  Update the warning message.

Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-09 14:43:27 -06:00
Shyam Prasad N
ce09f8d8a7 cifs: new mount option called retrans
We have several places in the code where we treat the
error -EAGAIN very differently. Some code retry for
arbitrary number of times.

Introducing this new mount option named "retrans", so
that all these handlers of -EAGAIN can retry a fixed
number of times. This applies only to soft mounts.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-19 10:31:57 -06:00
Quang Le
e6e43b8aa7 fs/smb/client: Reset password pointer to NULL
Forget to reset ctx->password to NULL will lead to bug like double free

Cc: stable@vger.kernel.org
Cc: Willy Tarreau <w@1wt.eu>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Quang Le <quanglex97@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-28 14:49:51 -05:00
Steve French
6a50d71d0f smb3: allow controlling maximum number of cached directories
Allow adjusting the maximum number of cached directories per share
(defaults to 16) via mount parm "max_cached_dirs"

Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-07 00:06:04 -05:00
Scott Mayhew
270d73e650 smb: client: fix null auth
Commit abdb1742a3 removed code that clears ctx->username when sec=none, so attempting
to mount with '-o sec=none' now fails with -EACCES.  Fix it by adding that logic to the
parsing of the 'sec' option, as well as checking if the mount is using null auth before
setting the username when parsing the 'user' option.

Fixes: abdb1742a3 ("cifs: get rid of mount options string parsing")
Cc: stable@vger.kernel.org
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-16 00:26:07 -05:00
Paulo Alcantara
49024ec879 smb: client: fix parsing of source mount option
Handle trailing and leading separators when parsing UNC and prefix
paths in smb3_parse_devname().  Then, store the sanitised paths in
smb3_fs_context::source.

This fixes the following cases

$ mount //srv/share// /mnt/1 -o ...
$ cat /mnt/1/d0/f0
cat: /mnt/1/d0/f0: Invalid argument

The -EINVAL was returned because the client sent SMB2_CREATE "\\d0\f0"
rather than SMB2_CREATE "\d0\f0".

$ mount //srv//share /mnt/1 -o ...
mount: Invalid argument

The -EINVAL was returned correctly although the client only realised
it after sending a couple of bad requests rather than bailing out
earlier when parsing mount options.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-28 11:48:56 -05:00
Steve French
38c8a9a520 smb: move client and server files to common directory fs/smb
Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko
and helper modules) to new fs/smb subdirectory:

   fs/cifs --> fs/smb/client
   fs/ksmbd --> fs/smb/server
   fs/smbfs_common --> fs/smb/common

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-24 16:29:21 -05:00