Commit Graph

657 Commits

Author SHA1 Message Date
ZhangGuoDong
827c92c15a smb/client: fix buffer size for smb311_posix_qinfo in SMB311_posix_query_info()
[ Upstream commit 9621b996e4 ]

SMB311_posix_query_info() is currently unused, but it may still be used in
some stable versions, so these changes are submitted as a separate patch.

Use `sizeof(struct smb311_posix_qinfo)` instead of sizeof its pointer,
so the allocated buffer matches the actual struct size.

Fixes: b1bc1874b8 ("smb311: Add support for SMB311 query info (non-compounded)")
Reported-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-13 17:20:43 +01:00
ZhangGuoDong
20a126dbd6 smb/client: fix buffer size for smb311_posix_qinfo in smb2_compound_op()
[ Upstream commit 12c43a062a ]

Use `sizeof(struct smb311_posix_qinfo)` instead of sizeof its pointer,
so the allocated buffer matches the actual struct size.

Fixes: 6a5f6592a0 ("SMB311: Add support for query info using posix extensions (level 100)")
Reported-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-13 17:20:43 +01:00
Thorsten Blum
b746a357ab smb: client: Don't log plaintext credentials in cifs_set_cifscreds
commit 2f37dc436d upstream.

When debug logging is enabled, cifs_set_cifscreds() logs the key
payload and exposes the plaintext username and password. Remove the
debug log to avoid exposing credentials.

Fixes: 8a8798a5ff ("cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts")
Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-13 17:20:36 +01:00
Paulo Alcantara
5b3aa73843 smb: client: fix broken multichannel with krb5+signing
commit d9d1e319b3 upstream.

When mounting a share with 'multichannel,max_channels=n,sec=krb5i',
the client was duplicating signing key for all secondary channels,
thus making the server fail all commands sent from secondary channels
due to bad signatures.

Every channel has its own signing key, so when establishing a new
channel with krb5 auth, make sure to use the new session key as the
derived key to generate channel's signing key in SMB2_auth_kerberos().

Repro:

$ mount.cifs //srv/share /mnt -o multichannel,max_channels=4,sec=krb5i
$ sleep 5
$ umount /mnt
$ dmesg
  ...
  CIFS: VFS: sign fail cmd 0x5 message id 0x2
  CIFS: VFS: \\srv SMB signature verification returned error = -13
  CIFS: VFS: sign fail cmd 0x5 message id 0x2
  CIFS: VFS: \\srv SMB signature verification returned error = -13
  CIFS: VFS: sign fail cmd 0x4 message id 0x2
  CIFS: VFS: \\srv SMB signature verification returned error = -13

Reported-by: Xiaoli Feng <xifeng@redhat.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-13 17:20:35 +01:00
Henrique Carvalho
4a5c8e1b6a smb: client: fix cifs_pick_channel when channels are equally loaded
commit 663c28469d upstream.

cifs_pick_channel uses (start % chan_count) when channels are equally
loaded, but that can return a channel that failed the eligibility
checks.

Drop the fallback and return the scan-selected channel instead. If none
is eligible, keep the existing behavior of using the primary channel.

Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Acked-by: Meetakshi Setiya <msetiya@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-13 17:20:35 +01:00
Shyam Prasad N
1d731e5121 cifs: some missing initializations on replay
[ Upstream commit 14f66f4464 ]

In several places in the code, we have a label to signify
the start of the code where a request can be replayed if
necessary. However, some of these places were missing the
necessary reinitializations of certain local variables
before replay.

This change makes sure that these variables get initialized
after the label.

Cc: stable@vger.kernel.org
Reported-by: Yuchan Nam <entropy1110@gmail.com>
Tested-by: Yuchan Nam <entropy1110@gmail.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:21:58 -05:00
Shyam Prasad N
601dd3b797 cifs: Fix locking usage for tcon fields
[ Upstream commit 96c4af4185 ]

We used to use the cifs_tcp_ses_lock to protect a lot of objects
that are not just the server, ses or tcon lists. We later introduced
srv_lock, ses_lock and tc_lock to protect fields within the
corresponding structs. This was done to provide a more granular
protection and avoid unnecessary serialization.

There were still a couple of uses of cifs_tcp_ses_lock to provide
tcon fields. In this patch, I've replaced them with tc_lock.

Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:21:54 -05:00
Henrique Carvalho
ab6564f416 smb: client: prevent races in ->query_interfaces()
[ Upstream commit c3c06e42e1 ]

It was possible for two query interface works to be concurrently trying
to update the interfaces.

Prevent this by checking and updating iface_last_update under
iface_lock.

Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:20:52 -05:00
Henrique Carvalho
a20d029585 smb: client: add proper locking around ses->iface_last_update
[ Upstream commit e97dcac3dc ]

There is a missing ses->iface_lock in cifs_setup_session,
around ses->iface_last_update.

Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:20:52 -05:00
Stefan Metzmacher
e99f816a42 smb: client: correct value for smbd_max_fragmented_recv_size
[ Upstream commit 4a93d1ee2d ]

When we download a file without rdma offload or get
a large directly enumeration from the server,
the server might want to send up to smbd_max_fragmented_recv_size
bytes, but if it is too large all our recv buffers
might already be moved to the recv_io.reassembly.list
and we're no longer able to grant recv credits.

The maximum fragmented upper-layer payload receive size supported

Assume max_payload_per_credit is
smbd_max_receive_size - 24 = 1340

The maximum number would be
smbd_receive_credit_max * max_payload_per_credit

                      1340 * 255 = 341700 (0x536C4)

The minimum value from the spec is 131072 (0x20000)

For now we use the logic we used in ksmbd before:
                (1364 * 255) / 2 = 173910 (0x2A756)

Fixes: 03bee01d62 ("CIFS: SMBD: Add SMB Direct protocol initial values and constants")
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:20:11 -05:00
Paulo Alcantara
4d339b2190 smb: client: fix potential UAF and double free in smb2_open_file()
[ Upstream commit ebbbc4bfad ]

Zero out @err_iov and @err_buftype before retrying SMB2_open() to
prevent an UAF bug if @data != NULL, otherwise a double free.

Fixes: e3a4363302 ("smb/client: fix memory leak in smb2_open_file()")
Reported-by: David Howells <dhowells@redhat.com>
Closes: https://lore.kernel.org/r/2892312.1770306653@warthog.procyon.org.uk
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:19:26 -05:00
Henrique Carvalho
3eaa22d688 smb: client: split cached_fid bitfields to avoid shared-byte RMW races
commit ec306600d5 upstream.

is_open, has_lease and on_list are stored in the same bitfield byte in
struct cached_fid but are updated in different code paths that may run
concurrently. Bitfield assignments generate byte read–modify–write
operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can
restore stale values of the others.

A possible interleaving is:
    CPU1: load old byte (has_lease=1, on_list=1)
    CPU2: clear both flags (store 0)
    CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits

To avoid this class of races, convert these flags to separate bool
fields.

Cc: stable@vger.kernel.org
Fixes: ebe98f1447 ("cifs: enable caching of directories for which a lease is held")
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-16 10:18:43 +01:00
ChenXiaoSong
b64e3b5d8d smb/client: fix memory leak in smb2_open_file()
[ Upstream commit e3a4363302 ]

Reproducer:

  1. server: directories are exported read-only
  2. client: mount -t cifs //${server_ip}/export /mnt
  3. client: dd if=/dev/zero of=/mnt/file bs=512 count=1000 oflag=direct
  4. client: umount /mnt
  5. client: sleep 1
  6. client: modprobe -r cifs

The error message is as follows:

  =============================================================================
  BUG cifs_small_rq (Not tainted): Objects remaining on __kmem_cache_shutdown()
  -----------------------------------------------------------------------------

  Object 0x00000000d47521be @offset=14336
  ...
  WARNING: mm/slub.c:1251 at __kmem_cache_shutdown+0x34e/0x440, CPU#0: modprobe/1577
  ...
  Call Trace:
   <TASK>
   kmem_cache_destroy+0x94/0x190
   cifs_destroy_request_bufs+0x3e/0x50 [cifs]
   cleanup_module+0x4e/0x540 [cifs]
   __se_sys_delete_module+0x278/0x400
   __x64_sys_delete_module+0x5f/0x70
   x64_sys_call+0x2299/0x2ff0
   do_syscall_64+0x89/0x350
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  ...
  kmem_cache_destroy cifs_small_rq: Slab cache still has objects when called from cifs_destroy_request_bufs+0x3e/0x50 [cifs]
  WARNING: mm/slab_common.c:532 at kmem_cache_destroy+0x16b/0x190, CPU#0: modprobe/1577

Link: https://lore.kernel.org/linux-cifs/9751f02d-d1df-4265-a7d6-b19761b21834@linux.dev/T/#mf14808c144448b715f711ce5f0477a071f08eaf6
Fixes: e255612b5e ("cifs: Add fallback for SMB2 CREATE without FILE_READ_ATTRIBUTES")
Reported-by: Paulo Alcantara <pc@manguebit.org>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-11 13:40:24 +01:00
ChenXiaoSong
261233f765 smb/client: fix NT_STATUS_NO_DATA_DETECTED value
[ Upstream commit a1237c203f ]

This was reported by the KUnit tests in the later patches.

See MS-ERREF 2.3.1 STATUS_NO_DATA_DETECTED. Keep it consistent with the
value in the documentation.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:31:19 +01:00
ChenXiaoSong
596d1b9686 smb/client: fix NT_STATUS_DEVICE_DOOR_OPEN value
[ Upstream commit b2b50fca34 ]

This was reported by the KUnit tests in the later patches.

See MS-ERREF 2.3.1 STATUS_DEVICE_DOOR_OPEN. Keep it consistent with the
value in the documentation.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:31:19 +01:00
ChenXiaoSong
b1dd686016 smb/client: fix NT_STATUS_UNABLE_TO_FREE_VM value
[ Upstream commit 9f99caa895 ]

This was reported by the KUnit tests in the later patches.

See MS-ERREF 2.3.1 STATUS_UNABLE_TO_FREE_VM. Keep it consistent with the
value in the documentation.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:31:19 +01:00
Zilin Guan
5679cc90bb cifs: Fix memory and information leak in smb3_reconfigure()
[ Upstream commit cb6d5aa9c0 ]

In smb3_reconfigure(), if smb3_sync_session_ctx_passwords() fails, the
function returns immediately without freeing and erasing the newly
allocated new_password and new_password2. This causes both a memory leak
and a potential information leak.

Fix this by calling kfree_sensitive() on both password buffers before
returning in this error case.

Fixes: 0f0e357902 ("cifs: during remount, make sure passwords are in sync")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:14:13 +01:00
David Howells
341d5aa3f0 cifs: Fix handling of a beyond-EOF DIO/unbuffered read over SMB2
[ Upstream commit 4ae4dde6f3 ]

If a DIO read or an unbuffered read request extends beyond the EOF, the
server will return a short read and a status code indicating that EOF was
hit, which gets translated to -ENODATA.  Note that the client does not cap
the request at i_size, but asks for the amount requested in case there's a
race on the server with a third party.

Now, on the client side, the request will get split into multiple
subrequests if rsize is smaller than the full request size.  A subrequest
that starts before or at the EOF and returns short data up to the EOF will
be correctly handled, with the NETFS_SREQ_HIT_EOF flag being set,
indicating to netfslib that we can't read more.

If a subrequest, however, starts after the EOF and not at it, HIT_EOF will
not be flagged, its error will be set to -ENODATA and it will be abandoned.
This will cause the request as a whole to fail with -ENODATA.

Fix this by setting NETFS_SREQ_HIT_EOF on any subrequest that lies beyond
the EOF marker.

Fixes: 1da29f2c39 ("netfs, cifs: Fix handling of short DIO read")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-18 13:55:20 +01:00
Yiqi Sun
ef9b1e6b8f smb: fix invalid username check in smb3_fs_context_parse_param()
[ Upstream commit ed6612165b ]

Since the maximum return value of strnlen(..., CIFS_MAX_USERNAME_LEN)
is CIFS_MAX_USERNAME_LEN, length check in smb3_fs_context_parse_param()
is always FALSE and invalid.

Fix the comparison in if statement.

Signed-off-by: Yiqi Sun <sunyiqixm@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-12 18:37:20 +01:00
Paulo Alcantara
f15288c137 smb: client: fix memory leak in cifs_construct_tcon()
commit 3184b6a5a2 upstream.

When having a multiuser mount with domain= specified and using
cifscreds, cifs_set_cifscreds() will end up setting @ctx->domainname,
so it needs to be freed before leaving cifs_construct_tcon().

This fixes the following memory leak reported by kmemleak:

  mount.cifs //srv/share /mnt -o domain=ZELDA,multiuser,...
  su - testuser
  cifscreds add -d ZELDA -u testuser
  ...
  ls /mnt/1
  ...
  umount /mnt
  echo scan > /sys/kernel/debug/kmemleak
  cat /sys/kernel/debug/kmemleak
  unreferenced object 0xffff8881203c3f08 (size 8):
    comm "ls", pid 5060, jiffies 4307222943
    hex dump (first 8 bytes):
      5a 45 4c 44 41 00 cc cc                          ZELDA...
    backtrace (crc d109a8cf):
      __kmalloc_node_track_caller_noprof+0x572/0x710
      kstrdup+0x3a/0x70
      cifs_sb_tlink+0x1209/0x1770 [cifs]
      cifs_get_fattr+0xe1/0xf50 [cifs]
      cifs_get_inode_info+0xb5/0x240 [cifs]
      cifs_revalidate_dentry_attr+0x2d1/0x470 [cifs]
      cifs_getattr+0x28e/0x450 [cifs]
      vfs_getattr_nosec+0x126/0x180
      vfs_statx+0xf6/0x220
      do_statx+0xab/0x110
      __x64_sys_statx+0xd5/0x130
      do_syscall_64+0xbb/0x380
      entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: f2aee329a6 ("cifs: set domainName when a domain-key is used in multiuser")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Jay Shin <jaeshin@redhat.com>
Cc: stable@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:24:59 +09:00
Henrique Carvalho
1ebfea90f9 smb: client: fix incomplete backport in cfids_invalidation_worker()
The previous commit bdb596ceb4 ("smb: client: fix potential UAF in
smb2_close_cached_fid()") was an incomplete backport and missed one
kref_put() call in cfids_invalidation_worker() that should have been
converted to close_cached_dir().

Fixes: 065bd62412 ("smb: client: fix potential UAF in smb2_close_cached_fid()")"
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-01 11:43:38 +01:00
Steve French
cfc16a0fb0 cifs: fix typo in enable_gcm_256 module parameter
[ Upstream commit f765fdfcd8 ]

Fix typo in description of enable_gcm_256 module parameter

Suggested-by: Thomas Spear <speeddymon@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01 11:43:35 +01:00
Shaurya Rane
48d6929027 cifs: fix memory leak in smb3_fs_context_parse_param error path
[ Upstream commit 7e4d9120cf ]

Add proper cleanup of ctx->source and fc->source to the
cifs_parse_mount_err error handler. This ensures that memory allocated
for the source strings is correctly freed on all error paths, matching
the cleanup already performed in the success path by
smb3_cleanup_fs_context_contents().
Pointers are also set to NULL after freeing to prevent potential
double-free issues.

This change fixes a memory leak originally detected by syzbot. The
leak occurred when processing Opt_source mount options if an error
happened after ctx->source and fc->source were successfully
allocated but before the function completed.

The specific leak sequence was:
1. ctx->source = smb3_fs_context_fullpath(ctx, '/') allocates memory
2. fc->source = kstrdup(ctx->source, GFP_KERNEL) allocates more memory
3. A subsequent error jumps to cifs_parse_mount_err
4. The old error handler freed passwords but not the source strings,
causing the memory to leak.

This issue was not addressed by commit e8c73eb7db ("cifs: client:
fix memory leak in smb3_fs_context_parse_param"), which only fixed
leaks from repeated fsconfig() calls but not this error path.

Patch updated with minor change suggested by kernel test robot

Reported-by: syzbot+87be6809ed9bf6d718e3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=87be6809ed9bf6d718e3
Fixes: 24e0a1eff9 ("cifs: switch to new mount api")
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01 11:43:34 +01:00
Henrique Carvalho
7b39fa2c3b smb: client: introduce close_cached_dir_locked()
commit a9d1f38df7 upstream.

Replace close_cached_dir() calls under cfid_list_lock with a new
close_cached_dir_locked() variant that uses kref_put() instead of
kref_put_lock() to avoid recursive locking when dropping references.

While the existing code works if the refcount >= 2 invariant holds,
this area has proven error-prone. Make deadlocks impossible and WARN
on invariant violations.

Cc: stable@vger.kernel.org
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-01 11:43:22 +01:00
Henrique Carvalho
21b7af43f1 smb: client: fix cifs_pick_channel when channel needs reconnect
commit 79280191c2 upstream.

cifs_pick_channel iterates candidate channels using cur. The
reconnect-state test mistakenly used a different variable.

This checked the wrong slot and would cause us to skip a healthy channel
and to dispatch on one that needs reconnect, occasionally failing
operations when a channel was down.

Fix by replacing for the correct variable.

Fixes: fc43a8ac39 ("cifs: cifs_pick_channel should try selecting active channels")
Cc: stable@vger.kernel.org
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24 10:36:02 +01:00
Edward Adam Davis
48c1734157 cifs: client: fix memory leak in smb3_fs_context_parse_param
commit e8c73eb7db upstream.

The user calls fsconfig twice, but when the program exits, free() only
frees ctx->source for the second fsconfig, not the first.
Regarding fc->source, there is no code in the fs context related to its
memory reclamation.

To fix this memory leak, release the source memory corresponding to ctx
or fc before each parsing.

syzbot reported:
BUG: memory leak
unreferenced object 0xffff888128afa360 (size 96):
  backtrace (crc 79c9c7ba):
    kstrdup+0x3c/0x80 mm/util.c:84
    smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444

BUG: memory leak
unreferenced object 0xffff888112c7d900 (size 96):
  backtrace (crc 79c9c7ba):
    smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629
    smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438

Reported-by: syzbot+72afd4c236e6bc3f4bac@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=72afd4c236e6bc3f4bac
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24 10:36:01 +01:00
Shuhao Fu
fbb9ccd574 smb: client: fix refcount leak in smb2_set_path_attr
[ Upstream commit b540de9e3b ]

Fix refcount leak in `smb2_set_path_attr` when path conversion fails.

Function `cifs_get_writable_path` returns `cfile` with its reference
counter `cfile->count` increased on success. Function `smb2_compound_op`
would decrease the reference counter for `cfile`, as stated in its
comment. By calling `smb2_rename_path`, the reference counter of `cfile`
would leak if `cifs_convert_path_to_utf16` fails in `smb2_set_path_attr`.

Fixes: 8de9e86c67 ("cifs: create a helper to find a writeable handle by path name")
Acked-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24 10:35:45 +01:00
Henrique Carvalho
065bd62412 smb: client: fix potential UAF in smb2_close_cached_fid()
commit 734e99623c upstream.

find_or_create_cached_dir() could grab a new reference after kref_put()
had seen the refcount drop to zero but before cfid_list_lock is acquired
in smb2_close_cached_fid(), leading to use-after-free.

Switch to kref_put_lock() so cfid_release() is called with
cfid_list_lock held, closing that gap.

Fixes: ebe98f1447 ("cifs: enable caching of directories for which a lease is held")
Cc: stable@vger.kernel.org
Reported-by: Jay Shin <jaeshin@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13 15:34:40 -05:00
Joshua Rogers
3d82cb8465 smb: client: validate change notify buffer before copy
commit 4012abe8a7 upstream.

SMB2_change_notify called smb2_validate_iov() but ignored the return
code, then kmemdup()ed using server provided OutputBufferOffset/Length.

Check the return of smb2_validate_iov() and bail out on error.

Discovered with help from the ZeroPath security tooling.

Signed-off-by: Joshua Rogers <linux@joshua.hu>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: stable@vger.kernel.org
Fixes: e3e9463414 ("smb3: improve SMB3 change notification support")
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13 15:34:40 -05:00
Fiona Ebner
ecda324c28 smb: client: transport: avoid reconnects triggered by pending task work
[ Upstream commit 00be6f26a2 ]

When io_uring is used in the same task as CIFS, there might be
unnecessary reconnects, causing issues in user-space applications
like QEMU with a log like:

> CIFS: VFS: \\10.10.100.81 Error -512 sending data on socket to server

Certain io_uring completions might be added to task_work with
notify_method being TWA_SIGNAL and thus TIF_NOTIFY_SIGNAL is set for
the task.

In __smb_send_rqst(), signals are masked before calling
smb_send_kvec(), but the masking does not apply to TIF_NOTIFY_SIGNAL.

If sk_stream_wait_memory() is reached via sock_sendmsg() while
TIF_NOTIFY_SIGNAL is set, signal_pending(current) will evaluate to
true there, and -EINTR will be propagated all the way from
sk_stream_wait_memory() to sock_sendmsg() in smb_send_kvec().
Afterwards, __smb_send_rqst() will see that not everything was written
and reconnect.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-13 15:34:32 -05:00
Henrique Carvalho
327f89c216 smb: client: fix potential cfid UAF in smb2_query_info_compound
commit 5c76f9961c upstream.

When smb2_query_info_compound() retries, a previously allocated cfid may
have been freed in the first attempt.
Because cfid wasn't reset on replay, later cleanup could act on a stale
pointer, leading to a potential use-after-free.

Reinitialize cfid to NULL under the replay label.

Example trace (trimmed):

refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 11224 at ../lib/refcount.c:28 refcount_warn_saturate+0x9c/0x110
[...]
RIP: 0010:refcount_warn_saturate+0x9c/0x110
[...]
Call Trace:
 <TASK>
 smb2_query_info_compound+0x29c/0x5c0 [cifs f90b72658819bd21c94769b6a652029a07a7172f]
 ? step_into+0x10d/0x690
 ? __legitimize_path+0x28/0x60
 smb2_queryfs+0x6a/0xf0 [cifs f90b72658819bd21c94769b6a652029a07a7172f]
 smb311_queryfs+0x12d/0x140 [cifs f90b72658819bd21c94769b6a652029a07a7172f]
 ? kmem_cache_alloc+0x18a/0x340
 ? getname_flags+0x46/0x1e0
 cifs_statfs+0x9f/0x2b0 [cifs f90b72658819bd21c94769b6a652029a07a7172f]
 statfs_by_dentry+0x67/0x90
 vfs_statfs+0x16/0xd0
 user_statfs+0x54/0xa0
 __do_sys_statfs+0x20/0x50
 do_syscall_64+0x58/0x80

Cc: stable@kernel.org
Fixes: 4f1fffa237 ("cifs: commands that are retried should have replay flag set")
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Acked-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13 15:33:56 -05:00
David Howells
c199595db5 cifs: Fix TCP_Server_Info::credits to be signed
commit 5b2ff4873a upstream.

Fix TCP_Server_Info::credits to be signed, just as echo_credits and
oplock_credits are.  This also fixes what ought to get at least a
compilation warning if not an outright error in *get_credits_field() as a
pointer to the unsigned server->credits field is passed back as a pointer
to a signed int.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Acked-by: Pavel Shilovskiy <pshilovskiy@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29 14:08:56 +01:00
Eugene Korenevsky
8bc4a8d39b cifs: parse_dfs_referrals: prevent oob on malformed input
commit 6447b0e355 upstream.

Malicious SMB server can send invalid reply to FSCTL_DFS_GET_REFERRALS

- reply smaller than sizeof(struct get_dfs_referral_rsp)
- reply with number of referrals smaller than NumberOfReferrals in the
header

Processing of such replies will cause oob.

Return -EINVAL error on such replies to prevent oob-s.

Signed-off-by: Eugene Korenevsky <ekorenevsky@aliyun.com>
Cc: stable@vger.kernel.org
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23 16:20:21 +02:00
Shuhao Fu
e15605b68b smb: client: Fix refcount leak for cifs_sb_tlink
commit c2b77f4220 upstream.

Fix three refcount inconsistency issues related to `cifs_sb_tlink`.

Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be
called after successful calls to `cifs_sb_tlink()`. Three calls fail to
update refcount accordingly, leading to possible resource leaks.

Fixes: 8ceb984379 ("CIFS: Move rename to ops struct")
Fixes: 2f1afe2599 ("cifs: Use smb 2 - 3 and cifsacl mount options getacl functions")
Fixes: 366ed846df ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function")
Cc: stable@vger.kernel.org
Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23 16:20:18 +02:00
Pali Rohár
fc2f2011d3 cifs: Query EA $LXMOD in cifs_query_path_info() for WSL reparse points
[ Upstream commit 057ac50638 ]

EA $LXMOD is required for WSL non-symlink reparse points.

Fixes: ef86ab131d ("cifs: Fix querying of WSL CHR and BLK reparse points over SMB1")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19 16:33:43 +02:00
Paulo Alcantara
7a411fb467 smb: client: fix missing timestamp updates after utime(2)
[ Upstream commit b95cd1bdf5 ]

Don't reuse open handle when changing timestamps to prevent the server
from disabling automatic timestamp updates as per MS-FSA 2.1.4.17.

---8<---
import os
import time

filename = '/mnt/foo'

def print_stat(prefix):
    st = os.stat(filename)
    print(prefix, ': ', time.ctime(st.st_atime), time.ctime(st.st_ctime))

fd = os.open(filename, os.O_CREAT|os.O_TRUNC|os.O_WRONLY, 0o644)
print_stat('old')
os.utime(fd, None)
time.sleep(2)
os.write(fd, b'foo')
os.close(fd)
time.sleep(2)
print_stat('new')
---8<---

Before patch:

$ mount.cifs //srv/share /mnt -o ...
$ python3 run.py
old :  Fri Oct  3 14:01:21 2025 Fri Oct  3 14:01:21 2025
new :  Fri Oct  3 14:01:21 2025 Fri Oct  3 14:01:21 2025

After patch:

$ mount.cifs //srv/share /mnt -o ...
$ python3 run.py
old :  Fri Oct  3 17:03:34 2025 Fri Oct  3 17:03:34 2025
new :  Fri Oct  3 17:03:36 2025 Fri Oct  3 17:03:36 2025

Fixes: b6f2a0f89d ("cifs: for compound requests, use open handle if possible")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19 16:33:43 +02:00
Fushuai Wang
6e2c760b64 cifs: Fix copy_to_iter return value check
[ Upstream commit 0cc380d0e1 ]

The return value of copy_to_iter() function will never be negative,
it is the number of bytes copied, or zero if nothing was copied.
Update the check to treat 0 as an error, and return -1 in that case.

Fixes: d08089f649 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Acked-by: Tom Talpey <tom@talpey.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19 16:33:43 +02:00
Enzo Matsumiya
7a8a8c1546 smb: client: fix crypto buffers in non-linear memory
[ Upstream commit 998a67b954 ]

The crypto API, through the scatterlist API, expects input buffers to be
in linear memory.  We handle this with the cifs_sg_set_buf() helper
that converts vmalloc'd memory to their corresponding pages.

However, when we allocate our aead_request buffer (@creq in
smb2ops.c::crypt_message()), we do so with kvzalloc(), which possibly
puts aead_request->__ctx in vmalloc area.

AEAD algorithm then uses ->__ctx for its private/internal data and
operations, and uses sg_set_buf() for such data on a few places.

This works fine as long as @creq falls into kmalloc zone (small
requests) or vmalloc'd memory is still within linear range.

Tasks' stacks are vmalloc'd by default (CONFIG_VMAP_STACK=y), so too
many tasks will increment the base stacks' addresses to a point where
virt_addr_valid(buf) will fail (BUG() in sg_set_buf()) when that
happens.

In practice: too many parallel reads and writes on an encrypted mount
will trigger this bug.

To fix this, always alloc @creq with kmalloc() instead.
Also drop the @sensitive_size variable/arguments since
kfree_sensitive() doesn't need it.

Backtrace:

[  945.272081] ------------[ cut here ]------------
[  945.272774] kernel BUG at include/linux/scatterlist.h:209!
[  945.273520] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI
[  945.274412] CPU: 7 UID: 0 PID: 56 Comm: kworker/u33:0 Kdump: loaded Not tainted 6.15.0-lku-11779-g8e9d6efccdd7-dirty #1 PREEMPT(voluntary)
[  945.275736] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
[  945.276877] Workqueue: writeback wb_workfn (flush-cifs-2)
[  945.277457] RIP: 0010:crypto_gcm_init_common+0x1f9/0x220
[  945.278018] Code: b0 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 c0 00 00 00 80 48 2b 05 5c 58 e5 00 e9 58 ff ff ff <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 48 c7 04 24 01 00 00 00 48 8b
[  945.279992] RSP: 0018:ffffc90000a27360 EFLAGS: 00010246
[  945.280578] RAX: 0000000000000000 RBX: ffffc90001d85060 RCX: 0000000000000030
[  945.281376] RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffc90081d85070
[  945.282145] RBP: ffffc90001d85010 R08: ffffc90001d85000 R09: 0000000000000000
[  945.282898] R10: ffffc90001d85090 R11: 0000000000001000 R12: ffffc90001d85070
[  945.283656] R13: ffff888113522948 R14: ffffc90001d85060 R15: ffffc90001d85010
[  945.284407] FS:  0000000000000000(0000) GS:ffff8882e66cf000(0000) knlGS:0000000000000000
[  945.285262] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  945.285884] CR2: 00007fa7ffdd31f4 CR3: 000000010540d000 CR4: 0000000000350ef0
[  945.286683] Call Trace:
[  945.286952]  <TASK>
[  945.287184]  ? crypt_message+0x33f/0xad0 [cifs]
[  945.287719]  crypto_gcm_encrypt+0x36/0xe0
[  945.288152]  crypt_message+0x54a/0xad0 [cifs]
[  945.288724]  smb3_init_transform_rq+0x277/0x300 [cifs]
[  945.289300]  smb_send_rqst+0xa3/0x160 [cifs]
[  945.289944]  cifs_call_async+0x178/0x340 [cifs]
[  945.290514]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]
[  945.291177]  smb2_async_writev+0x3e3/0x670 [cifs]
[  945.291759]  ? find_held_lock+0x32/0x90
[  945.292212]  ? netfs_advance_write+0xf2/0x310
[  945.292723]  netfs_advance_write+0xf2/0x310
[  945.293210]  netfs_write_folio+0x346/0xcc0
[  945.293689]  ? __pfx__raw_spin_unlock_irq+0x10/0x10
[  945.294250]  netfs_writepages+0x117/0x460
[  945.294724]  do_writepages+0xbe/0x170
[  945.295152]  ? find_held_lock+0x32/0x90
[  945.295600]  ? kvm_sched_clock_read+0x11/0x20
[  945.296103]  __writeback_single_inode+0x56/0x4b0
[  945.296643]  writeback_sb_inodes+0x229/0x550
[  945.297140]  __writeback_inodes_wb+0x4c/0xe0
[  945.297642]  wb_writeback+0x2f1/0x3f0
[  945.298069]  wb_workfn+0x300/0x490
[  945.298472]  process_one_work+0x1fe/0x590
[  945.298949]  worker_thread+0x1ce/0x3c0
[  945.299397]  ? __pfx_worker_thread+0x10/0x10
[  945.299900]  kthread+0x119/0x210
[  945.300285]  ? __pfx_kthread+0x10/0x10
[  945.300729]  ret_from_fork+0x119/0x1b0
[  945.301163]  ? __pfx_kthread+0x10/0x10
[  945.301601]  ret_from_fork_asm+0x1a/0x30
[  945.302055]  </TASK>

Fixes: d08089f649 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:00:20 +02:00
Sang-Heon Jeon
bfb1e2aad1 smb: client: fix wrong index reference in smb2_compound_op()
[ Upstream commit fbe2dc6a9c ]

In smb2_compound_op(), the loop that processes each command's response
uses wrong indices when accessing response bufferes.

This incorrect indexing leads to improper handling of command results.
Also, if incorrectly computed index is greather than or equal to
MAX_COMPOUND, it can cause out-of-bounds accesses.

Fixes: 3681c74d34 ("smb: client: handle lack of EA support in smb2_query_path_info()") # 6.14
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-02 13:44:12 +02:00
Stefan Metzmacher
922338efaa smb: client: fix smbdirect_recv_io leak in smbd_negotiate() error path
[ Upstream commit daac51c703 ]

During tests of another unrelated patch I was able to trigger this
error: Objects remaining on __kmem_cache_shutdown()

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-25 11:13:49 +02:00
Stefan Metzmacher
6ae90a2baf smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work)
[ Upstream commit d9dcbbcf91 ]

In smbd_destroy() we may destroy the memory so we better
wait until post_send_credits_work is no longer pending
and will never be started again.

I actually just hit the case using rxe:

WARNING: CPU: 0 PID: 138 at drivers/infiniband/sw/rxe/rxe_verbs.c:1032 rxe_post_recv+0x1ee/0x480 [rdma_rxe]
...
[ 5305.686979] [    T138]  smbd_post_recv+0x445/0xc10 [cifs]
[ 5305.687135] [    T138]  ? srso_alias_return_thunk+0x5/0xfbef5
[ 5305.687149] [    T138]  ? __kasan_check_write+0x14/0x30
[ 5305.687185] [    T138]  ? __pfx_smbd_post_recv+0x10/0x10 [cifs]
[ 5305.687329] [    T138]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 5305.687356] [    T138]  ? srso_alias_return_thunk+0x5/0xfbef5
[ 5305.687368] [    T138]  ? srso_alias_return_thunk+0x5/0xfbef5
[ 5305.687378] [    T138]  ? _raw_spin_unlock_irqrestore+0x11/0x60
[ 5305.687389] [    T138]  ? srso_alias_return_thunk+0x5/0xfbef5
[ 5305.687399] [    T138]  ? get_receive_buffer+0x168/0x210 [cifs]
[ 5305.687555] [    T138]  smbd_post_send_credits+0x382/0x4b0 [cifs]
[ 5305.687701] [    T138]  ? __pfx_smbd_post_send_credits+0x10/0x10 [cifs]
[ 5305.687855] [    T138]  ? __pfx___schedule+0x10/0x10
[ 5305.687865] [    T138]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[ 5305.687875] [    T138]  ? queue_delayed_work_on+0x8e/0xa0
[ 5305.687889] [    T138]  process_one_work+0x629/0xf80
[ 5305.687908] [    T138]  ? srso_alias_return_thunk+0x5/0xfbef5
[ 5305.687917] [    T138]  ? __kasan_check_write+0x14/0x30
[ 5305.687933] [    T138]  worker_thread+0x87f/0x1570
...

It means rxe_post_recv was called after rdma_destroy_qp().
This happened because put_receive_buffer() was triggered
by ib_drain_qp() and called:
queue_work(info->workqueue, &info->post_send_credits_work);

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-25 11:13:49 +02:00
Paulo Alcantara
b814660334 smb: client: fix filename matching of deferred files
[ Upstream commit 93ed9a2951 ]

Fix the following case where the client would end up closing both
deferred files (foo.tmp & foo) after unlink(foo) due to strstr() call
in cifs_close_deferred_file_under_dentry():

  fd1 = openat(AT_FDCWD, "foo", O_WRONLY|O_CREAT|O_TRUNC, 0666);
  fd2 = openat(AT_FDCWD, "foo.tmp", O_WRONLY|O_CREAT|O_TRUNC, 0666);
  close(fd1);
  close(fd2);
  unlink("foo");

Fixes: e3fc065682 ("cifs: Deferred close performance improvements")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Cc: Frank Sorenson <sorenson@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-25 11:13:49 +02:00
Makar Semyonov
1f797f062b cifs: prevent NULL pointer dereference in UTF16 conversion
commit 70bccd9855 upstream.

There can be a NULL pointer dereference bug here. NULL is passed to
__cifs_sfu_make_node without checks, which passes it unchecked to
cifs_strndup_to_utf16, which in turn passes it to
cifs_local_to_utf16_bytes where '*from' is dereferenced, causing a crash.

This patch adds a check for NULL 'src' in cifs_strndup_to_utf16 and
returns NULL early to prevent dereferencing NULL pointer.

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

Signed-off-by: Makar Semyonov <m.semenov@tssltd.ru>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-09 18:58:18 +02:00
Steve French
806fdb4422 smb3 client: fix return code mapping of remap_file_range
commit 0e08fa789d upstream.

We were returning -EOPNOTSUPP for various remap_file_range cases
but for some of these the copy_file_range_syscall() requires -EINVAL
to be returned (e.g. where source and target file ranges overlap when
source and target are the same file). This fixes xfstest generic/157
which was expecting EINVAL for that (and also e.g. for when the src
offset is beyond end of file).

Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-04 15:31:54 +02:00
Shuhao Fu
4735f5991f fs/smb: Fix inconsistent refcnt update
commit ab529e6ca1 upstream.

A possible inconsistent update of refcount was identified in `smb2_compound_op`.
Such inconsistent update could lead to possible resource leaks.

Why it is a possible bug:
1. In the comment section of the function, it clearly states that the
reference to `cfile` should be dropped after calling this function.
2. Every control flow path would check and drop the reference to
`cfile`, except the patched one.
3. Existing callers would not handle refcount update of `cfile` if
-ENOMEM is returned.

To fix the bug, an extra goto label "out" is added, to make sure that the
cleanup logic would always be respected. As the problem is caused by the
allocation failure of `vars`, the cleanup logic between label "finished"
and "out" can be safely ignored. According to the definition of function
`is_replayable_error`, the error code of "-ENOMEM" is not recoverable.
Therefore, the replay logic also gets ignored.

Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-04 15:31:54 +02:00
Paulo Alcantara
c9991af5e0 smb: client: fix race with concurrent opens in rename(2)
[ Upstream commit d84291fc74 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04 15:31:44 +02:00
Paulo Alcantara
c2c9d0ae69 smb: client: fix race with concurrent opens in unlink(2)
[ Upstream commit 0af1561b2d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04 15:31:44 +02:00
David Howells
4931fe2dbe cifs: Fix oops due to uninitialised variable
[ Upstream commit 453a6d2a68 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28 16:31:14 +02:00
Wang Zhaolong
5a9c806567 smb: client: fix netns refcount leak after net_passive changes
[ Upstream commit 59b33fab4c ]

After commit 5c70eb5c59 ("net: better track kernel sockets lifetime"),
kernel sockets now use net_passive reference counting. However, commit
95d2b9f693 ("Revert "smb: client: fix TCP timers deadlock after rmmod"")
restored the manual socket refcount manipulation without adapting to this
new mechanism, causing a memory leak.

The issue can be reproduced by[1]:
1. Creating a network namespace
2. Mounting and Unmounting CIFS within the namespace
3. Deleting the namespace

Some memory leaks may appear after a period of time following step 3.

unreferenced object 0xffff9951419f6b00 (size 256):
  comm "ip", pid 447, jiffies 4294692389 (age 14.730s)
  hex dump (first 32 bytes):
    1b 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 80 77 c2 44 51 99 ff ff  .........w.DQ...
  backtrace:
    __kmem_cache_alloc_node+0x30e/0x3d0
    __kmalloc+0x52/0x120
    net_alloc_generic+0x1d/0x30
    copy_net_ns+0x86/0x200
    create_new_namespaces+0x117/0x300
    unshare_nsproxy_namespaces+0x60/0xa0
    ksys_unshare+0x148/0x360
    __x64_sys_unshare+0x12/0x20
    do_syscall_64+0x59/0x110
    entry_SYSCALL_64_after_hwframe+0x78/0xe2
...
unreferenced object 0xffff9951442e7500 (size 32):
  comm "mount.cifs", pid 475, jiffies 4294693782 (age 13.343s)
  hex dump (first 32 bytes):
    40 c5 38 46 51 99 ff ff 18 01 96 42 51 99 ff ff  @.8FQ......BQ...
    01 00 00 00 6f 00 c5 07 6f 00 d8 07 00 00 00 00  ....o...o.......
  backtrace:
    __kmem_cache_alloc_node+0x30e/0x3d0
    kmalloc_trace+0x2a/0x90
    ref_tracker_alloc+0x8e/0x1d0
    sk_alloc+0x18c/0x1c0
    inet_create+0xf1/0x370
    __sock_create+0xd7/0x1e0
    generic_ip_connect+0x1d4/0x5a0 [cifs]
    cifs_get_tcp_session+0x5d0/0x8a0 [cifs]
    cifs_mount_get_session+0x47/0x1b0 [cifs]
    dfs_mount_share+0xfa/0xa10 [cifs]
    cifs_mount+0x68/0x2b0 [cifs]
    cifs_smb3_do_mount+0x10b/0x760 [cifs]
    smb3_get_tree+0x112/0x2e0 [cifs]
    vfs_get_tree+0x29/0xf0
    path_mount+0x2d4/0xa00
    __se_sys_mount+0x165/0x1d0

Root cause:
When creating kernel sockets, sk_alloc() calls net_passive_inc() for
sockets with sk_net_refcnt=0. The CIFS code manually converts kernel
sockets to user sockets by setting sk_net_refcnt=1, but doesn't call
the corresponding net_passive_dec(). This creates an imbalance in the
net_passive counter, which prevents the network namespace from being
destroyed when its last user reference is dropped. As a result, the
entire namespace and all its associated resources remain allocated.

Timeline of patches leading to this issue:
- commit ef7134c7fc ("smb: client: Fix use-after-free of network
  namespace.") in v6.12 fixed the original netns UAF by manually
  managing socket refcounts
- commit e9f2517a3e ("smb: client: fix TCP timers deadlock after
  rmmod") in v6.13 attempted to use kernel sockets but introduced
  TCP timer issues
- commit 5c70eb5c59 ("net: better track kernel sockets lifetime")
  in v6.14-rc5 introduced the net_passive mechanism with
  sk_net_refcnt_upgrade() for proper socket conversion
- commit 95d2b9f693 ("Revert "smb: client: fix TCP timers deadlock
  after rmmod"") in v6.15-rc3 reverted to manual refcount management
  without adapting to the new net_passive changes

Fix this by using sk_net_refcnt_upgrade() which properly handles the
net_passive counter when converting kernel sockets to user sockets.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=220343 [1]
Fixes: 95d2b9f693 ("Revert "smb: client: fix TCP timers deadlock after rmmod"")
Cc: stable@vger.kernel.org
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:57 +02:00
Shyam Prasad N
83e6c09b01 cifs: reset iface weights when we cannot find a candidate
commit 9d5eff7821 upstream.

We now do a weighted selection of server interfaces when allocating
new channels. The weights are decided based on the speed advertised.
The fulfilled weight for an interface is a counter that is used to
track the interface selection. It should be reset back to zero once
all interfaces fulfilling their weight.

In cifs_chan_update_iface, this reset logic was missing. As a result
when the server interface list changes, the client may not be able
to find a new candidate for other channels after all interfaces have
been fulfilled.

Fixes: a6d8fb54a5 ("cifs: distribute channels across interfaces based on speed")
Cc: <stable@vger.kernel.org>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:51 +02:00