Commit graph

615 commits

Author SHA1 Message Date
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
David Howells
ea1724dc0e cifs: Fix collect_sample() to handle any iterator type
[ Upstream commit b63335fb3d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-20 18:30:50 +02:00
Stefan Metzmacher
4191feb410 smb: client: don't call init_waitqueue_head(&info->conn_wait) twice in _smbd_get_connection
[ Upstream commit 550a194c59 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-20 18:30:49 +02:00
Pali Rohár
ec12068f10 cifs: Fix calling CIFSFindFirst() for root path without msearch
[ Upstream commit b460249b9a ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-20 18:30:40 +02:00
Stefan Metzmacher
a831c3e679 smb: client: don't wait for info->send_pending == 0 on error
commit 8c48e1c752 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:16 +02:00
Stefan Metzmacher
65969af6dd smb: client: let send_done() cleanup before calling smbd_disconnect_rdma_connection()
commit 5349ae5e05 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:16 +02:00
Wang Zhaolong
b3f7932c8e smb: client: remove redundant lstrp update in negotiate protocol
commit e19d8dd694 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:12 +02:00
Steve French
8de33d4d72 smb3: fix for slab out of bounds on mount to ksmbd
commit 7d34ec36ab upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:12 +02:00
Stefan Metzmacher
39f8e0cf17 smb: client: return an error if rdma_connect does not return within 5 seconds
[ Upstream commit 03537826f7 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:09 +02:00
Stefan Metzmacher
8c221b55d0 smb: client: let recv_done() avoid touching data_transfer after cleanup/move
[ Upstream commit 24eff17887 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:08 +02:00
Stefan Metzmacher
c5b3ce5cc7 smb: client: let recv_done() cleanup before notifying the callers.
[ Upstream commit bdd7afc6dc ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:08 +02:00
Stefan Metzmacher
501eed35ca smb: client: make sure we call ib_dma_unmap_single() only if we called ib_dma_map_single already
[ Upstream commit 047682c370 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:08 +02:00
Stefan Metzmacher
d6917b4349 smb: client: remove separate empty_packet_queue
[ Upstream commit 24b6afc36d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:08 +02:00
Stefan Metzmacher
e82d8825f7 smb: client: let smbd_post_send_iter() respect the peers max_send_size and transmit all data
commit 1944f6ab49 upstream.

We should not send smbdirect_data_transfer messages larger than
the negotiated max_send_size, typically 1364 bytes, which means
24 bytes of the smbdirect_data_transfer header + 1340 payload bytes.

This happened when doing an SMB2 write with more than 1340 bytes
(which is done inline as it's below rdma_readwrite_threshold).

It means the peer resets the connection.

When testing between cifs.ko and ksmbd.ko something like this
is logged:

client:

    CIFS: VFS: RDMA transport re-established
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    CIFS: VFS: \\carina Send error in SessSetup = -11
    smb2_reconnect: 12 callbacks suppressed
    CIFS: VFS: reconnect tcon failed rc = -11
    CIFS: VFS: reconnect tcon failed rc = -11
    CIFS: VFS: reconnect tcon failed rc = -11
    CIFS: VFS: SMB: Zero rsize calculated, using minimum value 65536

and:

    CIFS: VFS: RDMA transport re-established
    siw: got TERMINATE. layer 1, type 2, code 2
    CIFS: VFS: smbd_recv:1894 disconnected
    siw: got TERMINATE. layer 1, type 2, code 2

The ksmbd dmesg is showing things like:

    smb_direct: Recv error. status='local length error (1)' opcode=128
    smb_direct: disconnected
    smb_direct: Recv error. status='local length error (1)' opcode=128
    ksmbd: smb_direct: disconnected
    ksmbd: sock_read failed: -107

As smbd_post_send_iter() limits the transmitted number of bytes
we need loop over it in order to transmit the whole iter.

Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Meetakshi Setiya <msetiya@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: <stable+noautosel@kernel.org> # sp->max_send_size should be info->max_send_size in backports
Fixes: 3d78fe73fa ("cifs: Build the RDMA SGE list directly from an iterator")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-24 08:56:38 +02:00
Wang Zhaolong
09bce2138a smb: client: fix use-after-free in cifs_oplock_break
[ Upstream commit 705c79101c ]

A race condition can occur in cifs_oplock_break() leading to a
use-after-free of the cinode structure when unmounting:

  cifs_oplock_break()
    _cifsFileInfo_put(cfile)
      cifsFileInfo_put_final()
        cifs_sb_deactive()
          [last ref, start releasing sb]
            kill_sb()
              kill_anon_super()
                generic_shutdown_super()
                  evict_inodes()
                    dispose_list()
                      evict()
                        destroy_inode()
                          call_rcu(&inode->i_rcu, i_callback)
    spin_lock(&cinode->open_file_lock)  <- OK
                            [later] i_callback()
                              cifs_free_inode()
                                kmem_cache_free(cinode)
    spin_unlock(&cinode->open_file_lock)  <- UAF
    cifs_done_oplock_break(cinode)       <- UAF

The issue occurs when umount has already released its reference to the
superblock. When _cifsFileInfo_put() calls cifs_sb_deactive(), this
releases the last reference, triggering the immediate cleanup of all
inodes under RCU. However, cifs_oplock_break() continues to access the
cinode after this point, resulting in use-after-free.

Fix this by holding an extra reference to the superblock during the
entire oplock break operation. This ensures that the superblock and
its inodes remain valid until the oplock break completes.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=220309
Fixes: b98749cac4 ("CIFS: keep FileInfo handle live during oplock break")
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-24 08:56:30 +02:00
Wang Zhaolong
2a76bc2b24 smb: client: fix use-after-free in crypt_message when using async crypto
commit b220bed633 upstream.

The CVE-2024-50047 fix removed asynchronous crypto handling from
crypt_message(), assuming all crypto operations are synchronous.
However, when hardware crypto accelerators are used, this can cause
use-after-free crashes:

  crypt_message()
    // Allocate the creq buffer containing the req
    creq = smb2_get_aead_req(..., &req);

    // Async encryption returns -EINPROGRESS immediately
    rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);

    // Free creq while async operation is still in progress
    kvfree_sensitive(creq, ...);

Hardware crypto modules often implement async AEAD operations for
performance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS,
the operation completes asynchronously. Without crypto_wait_req(),
the function immediately frees the request buffer, leading to crashes
when the driver later accesses the freed memory.

This results in a use-after-free condition when the hardware crypto
driver later accesses the freed request structure, leading to kernel
crashes with NULL pointer dereferences.

The issue occurs because crypto_alloc_aead() with mask=0 doesn't
guarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in
the mask, async implementations can be selected.

Fix by restoring the async crypto handling:
- DECLARE_CRYPTO_WAIT(wait) for completion tracking
- aead_request_set_callback() for async completion notification
- crypto_wait_req() to wait for operation completion

This ensures the request buffer isn't freed until the crypto operation
completes, whether synchronous or asynchronous, while preserving the
CVE-2024-50047 fix.

Fixes: b0abcd65ec ("smb: client: fix UAF in async decryption")
Link: https://lore.kernel.org/all/8b784a13-87b0-4131-9ff9-7a8993538749@huaweicloud.com/
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-24 08:56:27 +02:00
Shyam Prasad N
631f9de9a7 cifs: all initializations for tcon should happen in tcon_info_alloc
commit 74ebd02163 upstream.

Today, a few work structs inside tcon are initialized inside
cifs_get_tcon and not in tcon_info_alloc. As a result, if a tcon
is obtained from tcon_info_alloc, but not called as a part of
cifs_get_tcon, we may trip over.

Cc: <stable@vger.kernel.org>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-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>
2025-07-10 16:05:12 +02:00
Philipp Kerling
7b02e09fc0 smb: client: fix readdir returning wrong type with POSIX extensions
commit b8f89cb723 upstream.

When SMB 3.1.1 POSIX Extensions are negotiated, userspace applications
using readdir() or getdents() calls without stat() on each individual file
(such as a simple "ls" or "find") would misidentify file types and exhibit
strange behavior such as not descending into directories. The reason for
this behavior is an oversight in the cifs_posix_to_fattr conversion
function. Instead of extracting the entry type for cf_dtype from the
properly converted cf_mode field, it tries to extract the type from the
PDU. While the wire representation of the entry mode is similar in
structure to POSIX stat(), the assignments of the entry types are
different. Applying the S_DT macro to cf_mode instead yields the correct
result. This is also what the equivalent function
smb311_posix_info_to_fattr in inode.c already does for stat() etc.; which
is why "ls -l" would give the correct file type but "ls" would not (as
identified by the colors).

Cc: stable@vger.kernel.org
Signed-off-by: Philipp Kerling <pkerling@casix.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-10 16:05:11 +02:00
Wang Zhaolong
2ba9db22d7 smb: client: fix race condition in negotiate timeout by using more precise timing
[ Upstream commit 266b5d02e1 ]

When the SMB server reboots and the client immediately accesses the mount
point, a race condition can occur that causes operations to fail with
"Host is down" error.

Reproduction steps:
  # Mount SMB share
  mount -t cifs //192.168.245.109/TEST /mnt/ -o xxxx
  ls /mnt

  # Reboot server
  ssh root@192.168.245.109 reboot
  ssh root@192.168.245.109 /path/to/cifs_server_setup.sh
  ssh root@192.168.245.109 systemctl stop firewalld

  # Immediate access fails
  ls /mnt
  ls: cannot access '/mnt': Host is down

  # But works if there is a delay

The issue is caused by a race condition between negotiate and reconnect.
The 20-second negotiate timeout mechanism can interfere with the normal
recovery process when both are triggered simultaneously.

  ls                              cifsd
---------------------------------------------------
 cifs_getattr
 cifs_revalidate_dentry
 cifs_get_inode_info
 cifs_get_fattr
 smb2_query_path_info
 smb2_compound_op
 SMB2_open_init
 smb2_reconnect
 cifs_negotiate_protocol
  smb2_negotiate
   cifs_send_recv
    smb_send_rqst
    wait_for_response
                            cifs_demultiplex_thread
                              cifs_read_from_socket
                              cifs_readv_from_socket
                                server_unresponsive
                                cifs_reconnect
                                  __cifs_reconnect
                                  cifs_abort_connection
                                    mid->mid_state = MID_RETRY_NEEDED
                                    cifs_wake_up_task
    cifs_sync_mid_result
     // case MID_RETRY_NEEDED
     rc = -EAGAIN;
   // In smb2_negotiate()
   rc = -EHOSTDOWN;

The server_unresponsive() timeout triggers cifs_reconnect(), which aborts
ongoing mid requests and causes the ls command to receive -EAGAIN, leading
to -EHOSTDOWN.

Fix this by introducing a dedicated `neg_start` field to
precisely tracks when the negotiate process begins. The timeout check
now uses this accurate timestamp instead of `lstrp`, ensuring that:

1. Timeout is only triggered after negotiate has actually run for 20s
2. The mechanism doesn't interfere with concurrent recovery processes
3. Uninitialized timestamps (value 0) don't trigger false timeouts

Fixes: 7ccc146546 ("smb: client: fix hang in wait_for_response() for negproto")
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:53 +02:00
Paulo Alcantara
9b55b7bdb0 smb: client: set missing retry flag in cifs_writev_callback()
[ Upstream commit 74ee76bea4 ]

Set NETFS_SREQ_NEED_RETRY flag to tell netfslib that the subreq needs
to be retried.

Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250701163852.2171681-9-dhowells@redhat.com
Tested-by: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: netfs@lists.linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:52 +02:00
Paulo Alcantara
590eb25749 smb: client: set missing retry flag in cifs_readv_callback()
[ Upstream commit 0e60bae24a ]

Set NETFS_SREQ_NEED_RETRY flag to tell netfslib that the subreq needs
to be retried.

Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250701163852.2171681-8-dhowells@redhat.com
Tested-by: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: netfs@lists.linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:52 +02:00
Paulo Alcantara
cd8c8c20de smb: client: set missing retry flag in smb2_writev_callback()
[ Upstream commit e67e75edeb ]

Set NETFS_SREQ_NEED_RETRY flag to tell netfslib that the subreq needs
to be retried.

Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250701163852.2171681-7-dhowells@redhat.com
Tested-by: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: netfs@lists.linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:52 +02:00
Paulo Alcantara
3f6932ef25 smb: client: fix warning when reconnecting channel
[ Upstream commit 3bbe467160 ]

When reconnecting a channel in smb2_reconnect_server(), a dummy tcon
is passed down to smb2_reconnect() with ->query_interface
uninitialized, so we can't call queue_delayed_work() on it.

Fix the following warning by ensuring that we're queueing the delayed
worker from correct tcon.

WARNING: CPU: 4 PID: 1126 at kernel/workqueue.c:2498 __queue_delayed_work+0x1d2/0x200
Modules linked in: cifs cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs]
CPU: 4 UID: 0 PID: 1126 Comm: kworker/4:0 Not tainted 6.16.0-rc3 #5 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-4.fc42 04/01/2014
Workqueue: cifsiod smb2_reconnect_server [cifs]
RIP: 0010:__queue_delayed_work+0x1d2/0x200
Code: 41 5e 41 5f e9 7f ee ff ff 90 0f 0b 90 e9 5d ff ff ff bf 02 00
00 00 e8 6c f3 07 00 89 c3 eb bd 90 0f 0b 90 e9 57 f> 0b 90 e9 65 fe
ff ff 90 0f 0b 90 e9 72 fe ff ff 90 0f 0b 90 e9
RSP: 0018:ffffc900014afad8 EFLAGS: 00010003
RAX: 0000000000000000 RBX: ffff888124d99988 RCX: ffffffff81399cc1
RDX: dffffc0000000000 RSI: ffff888114326e00 RDI: ffff888124d999f0
RBP: 000000000000ea60 R08: 0000000000000001 R09: ffffed10249b3331
R10: ffff888124d9998f R11: 0000000000000004 R12: 0000000000000040
R13: ffff888114326e00 R14: ffff888124d999d8 R15: ffff888114939020
FS:  0000000000000000(0000) GS:ffff88829f7fe000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7a2b4038 CR3: 0000000120a6f000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
 <TASK>
 queue_delayed_work_on+0xb4/0xc0
 smb2_reconnect+0xb22/0xf50 [cifs]
 smb2_reconnect_server+0x413/0xd40 [cifs]
 ? __pfx_smb2_reconnect_server+0x10/0x10 [cifs]
 ? local_clock_noinstr+0xd/0xd0
 ? local_clock+0x15/0x30
 ? lock_release+0x29b/0x390
 process_one_work+0x4c5/0xa10
 ? __pfx_process_one_work+0x10/0x10
 ? __list_add_valid_or_report+0x37/0x120
 worker_thread+0x2f1/0x5a0
 ? __kthread_parkme+0xde/0x100
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x1fe/0x380
 ? kthread+0x10f/0x380
 ? __pfx_kthread+0x10/0x10
 ? local_clock_noinstr+0xd/0xd0
 ? ret_from_fork+0x1b/0x1f0
 ? local_clock+0x15/0x30
 ? lock_release+0x29b/0x390
 ? rcu_is_watching+0x20/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x15b/0x1f0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>
irq event stamp: 1116206
hardirqs last  enabled at (1116205): [<ffffffff8143af42>] __up_console_sem+0x52/0x60
hardirqs last disabled at (1116206): [<ffffffff81399f0e>] queue_delayed_work_on+0x6e/0xc0
softirqs last  enabled at (1116138): [<ffffffffc04562fd>] __smb_send_rqst+0x42d/0x950 [cifs]
softirqs last disabled at (1116136): [<ffffffff823d35e1>] release_sock+0x21/0xf0

Cc: linux-cifs@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Fixes: 42ca547b13 ("cifs: do not disable interface polling on failure")
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:51 +02:00
David Howells
bced02aca3 cifs: Fix reading into an ITER_FOLIOQ from the smbdirect code
[ Upstream commit 263debecb4 ]

When performing a file read from RDMA, smbd_recv() prints an "Invalid msg
type 4" error and fails the I/O.  This is due to the switch-statement there
not handling the ITER_FOLIOQ handed down from netfslib.

Fix this by collapsing smbd_recv_buf() and smbd_recv_page() into
smbd_recv() and just using copy_to_iter() instead of memcpy().  This
future-proofs the function too, in case more ITER_* types are added.

Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Tom Talpey <tom@talpey.com>
cc: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Matthew Wilcox <willy@infradead.org>
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>
2025-07-06 11:01:42 +02:00
David Howells
87dcc7e33f cifs: Fix the smbd_response slab to allow usercopy
[ Upstream commit 43e7e284fc ]

The handling of received data in the smbdirect client code involves using
copy_to_iter() to copy data from the smbd_reponse struct's packet trailer
to a folioq buffer provided by netfslib that encapsulates a chunk of
pagecache.

If, however, CONFIG_HARDENED_USERCOPY=y, this will result in the checks
then performed in copy_to_iter() oopsing with something like the following:

 CIFS: Attempting to mount //172.31.9.1/test
 CIFS: VFS: RDMA transport established
 usercopy: Kernel memory exposure attempt detected from SLUB object 'smbd_response_0000000091e24ea1' (offset 81, size 63)!
 ------------[ cut here ]------------
 kernel BUG at mm/usercopy.c:102!
 ...
 RIP: 0010:usercopy_abort+0x6c/0x80
 ...
 Call Trace:
  <TASK>
  __check_heap_object+0xe3/0x120
  __check_object_size+0x4dc/0x6d0
  smbd_recv+0x77f/0xfe0 [cifs]
  cifs_readv_from_socket+0x276/0x8f0 [cifs]
  cifs_read_from_socket+0xcd/0x120 [cifs]
  cifs_demultiplex_thread+0x7e9/0x2d50 [cifs]
  kthread+0x396/0x830
  ret_from_fork+0x2b8/0x3b0
  ret_from_fork_asm+0x1a/0x30

The problem is that the smbd_response slab's packet field isn't marked as
being permitted for usercopy.

Fix this by passing parameters to kmem_slab_create() to indicate that
copy_to_iter() is permitted from the packet region of the smbd_response
slab objects, less the header space.

Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Reported-by: Stefan Metzmacher <metze@samba.org>
Link: https://lore.kernel.org/r/acb7f612-df26-4e2a-a35d-7cd040f513e1@samba.org/
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Tested-by: Stefan Metzmacher <metze@samba.org>
cc: Paulo Alcantara <pc@manguebit.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>
2025-07-06 11:01:42 +02:00
Stefan Metzmacher
b8ddcca439 smb: client: make use of common smbdirect_socket_parameters
[ Upstream commit cc55f65dd3 ]

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: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Meetakshi Setiya <meetakshisetiyaoss@gmail.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>
Stable-dep-of: 43e7e284fc ("cifs: Fix the smbd_response slab to allow usercopy")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:42 +02:00
Stefan Metzmacher
69cafc413c smb: smbdirect: introduce smbdirect_socket_parameters
[ Upstream commit dce8047f47 ]

This is the next step in the direction of a common smbdirect layer.

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: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Meetakshi Setiya <meetakshisetiyaoss@gmail.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>
Stable-dep-of: 43e7e284fc ("cifs: Fix the smbd_response slab to allow usercopy")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:42 +02:00
Stefan Metzmacher
c39639bc77 smb: client: make use of common smbdirect_socket
[ Upstream commit c3011b9a7d ]

This is the next step in the direction of a common smbdirect layer.
Currently only structures are shared, but that will change
over time until everything is shared.

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: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Meetakshi Setiya <meetakshisetiyaoss@gmail.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>
Stable-dep-of: 43e7e284fc ("cifs: Fix the smbd_response slab to allow usercopy")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:42 +02:00
Stefan Metzmacher
6509de31b1 smb: client: make use of common smbdirect_pdu.h
[ Upstream commit 64946d5be6 ]

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: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Meetakshi Setiya <meetakshisetiyaoss@gmail.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>
Stable-dep-of: 43e7e284fc ("cifs: Fix the smbd_response slab to allow usercopy")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:42 +02:00
Paulo Alcantara
7f3ead8ebc smb: client: fix potential deadlock when reconnecting channels
[ Upstream commit 711741f94a ]

Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order
and prevent the following deadlock from happening

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3-build2+ #1301 Tainted: G S      W
------------------------------------------------------
cifsd/6055 is trying to acquire lock:
ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200

but task is already holding lock:
ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:
       validate_chain+0x1cf/0x270
       __lock_acquire+0x60e/0x780
       lock_acquire.part.0+0xb4/0x1f0
       _raw_spin_lock+0x2f/0x40
       cifs_setup_session+0x81/0x4b0
       cifs_get_smb_ses+0x771/0x900
       cifs_mount_get_session+0x7e/0x170
       cifs_mount+0x92/0x2d0
       cifs_smb3_do_mount+0x161/0x460
       smb3_get_tree+0x55/0x90
       vfs_get_tree+0x46/0x180
       do_new_mount+0x1b0/0x2e0
       path_mount+0x6ee/0x740
       do_mount+0x98/0xe0
       __do_sys_mount+0x148/0x180
       do_syscall_64+0xa4/0x260
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:
       validate_chain+0x1cf/0x270
       __lock_acquire+0x60e/0x780
       lock_acquire.part.0+0xb4/0x1f0
       _raw_spin_lock+0x2f/0x40
       cifs_match_super+0x101/0x320
       sget+0xab/0x270
       cifs_smb3_do_mount+0x1e0/0x460
       smb3_get_tree+0x55/0x90
       vfs_get_tree+0x46/0x180
       do_new_mount+0x1b0/0x2e0
       path_mount+0x6ee/0x740
       do_mount+0x98/0xe0
       __do_sys_mount+0x148/0x180
       do_syscall_64+0xa4/0x260
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:
       check_noncircular+0x95/0xc0
       check_prev_add+0x115/0x2f0
       validate_chain+0x1cf/0x270
       __lock_acquire+0x60e/0x780
       lock_acquire.part.0+0xb4/0x1f0
       _raw_spin_lock+0x2f/0x40
       cifs_signal_cifsd_for_reconnect+0x134/0x200
       __cifs_reconnect+0x8f/0x500
       cifs_handle_standard+0x112/0x280
       cifs_demultiplex_thread+0x64d/0xbc0
       kthread+0x2f7/0x310
       ret_from_fork+0x2a/0x230
       ret_from_fork_asm+0x1a/0x30

other info that might help us debug this:

Chain exists of:
  &tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ret_buf->chan_lock);
                               lock(&ret_buf->ses_lock);
                               lock(&ret_buf->chan_lock);
  lock(&tcp_ses->srv_lock);

 *** DEADLOCK ***

3 locks held by cifsd/6055:
 #0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200
 #1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200
 #2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200

Cc: linux-cifs@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Fixes: d7d7a66aac ("cifs: avoid use of global locks for high contention data")
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:41 +02:00
Stefan Metzmacher
f85c7138f7 smb: client: remove \t from TP_printk statements
commit e97f9540ce upstream.

The generate '[FAILED TO PARSE]' strings in trace-cmd report output like this:

  rm-5298  [001]  6084.533748493: smb3_exit_err:        [FAILED TO PARSE] xid=972 func_name=cifs_rmdir rc=-39
  rm-5298  [001]  6084.533959234: smb3_enter:           [FAILED TO PARSE] xid=973 func_name=cifs_closedir
  rm-5298  [001]  6084.533967630: smb3_close_enter:     [FAILED TO PARSE] xid=973 fid=94489281833 tid=1 sesid=96758029877361
  rm-5298  [001]  6084.534004008: smb3_cmd_enter:       [FAILED TO PARSE] tid=1 sesid=96758029877361 cmd=6 mid=566
  rm-5298  [001]  6084.552248232: smb3_cmd_done:        [FAILED TO PARSE] tid=1 sesid=96758029877361 cmd=6 mid=566
  rm-5298  [001]  6084.552280542: smb3_close_done:      [FAILED TO PARSE] xid=973 fid=94489281833 tid=1 sesid=96758029877361
  rm-5298  [001]  6084.552316034: smb3_exit_done:       [FAILED TO PARSE] xid=973 func_name=cifs_closedir

Cc: stable@vger.kernel.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-06 11:01:38 +02:00
Pali Rohár
61dd1dcf05 cifs: Fix encoding of SMB1 Session Setup NTLMSSP Request in non-UNICODE mode
[ Upstream commit 6510ef4230 ]

SMB1 Session Setup NTLMSSP Request in non-UNICODE mode is similar to
UNICODE mode, just strings are encoded in ASCII and not in UTF-16.

With this change it is possible to setup SMB1 session with NTLM
authentication in non-UNICODE mode with Windows SMB server.

This change fixes mounting SMB1 servers with -o nounicode mount option
together with -o sec=ntlmssp mount option (which is the default sec=).

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:31 +02:00
Pali Rohár
ef4b3a7bf9 cifs: Fix cifs_query_path_info() for Windows NT servers
[ Upstream commit a3e771afbb ]

For TRANS2 QUERY_PATH_INFO request when the path does not exist, the
Windows NT SMB server returns error response STATUS_OBJECT_NAME_NOT_FOUND
or ERRDOS/ERRbadfile without the SMBFLG_RESPONSE flag set. Similarly it
returns STATUS_DELETE_PENDING when the file is being deleted. And looks
like that any error response from TRANS2 QUERY_PATH_INFO does not have
SMBFLG_RESPONSE flag set.

So relax check in check_smb_hdr() for detecting if the packet is response
for this special case.

This change fixes stat() operation against Windows NT SMB servers and also
all operations which depends on -ENOENT result from stat like creat() or
mkdir().

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:31 +02:00
Pali Rohár
f80fdf48b8 cifs: Correctly set SMB1 SessionKey field in Session Setup Request
[ Upstream commit 89381c72d5 ]

[MS-CIFS] specification in section 2.2.4.53.1 where is described
SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says:

    The client MUST set this field to be equal to the SessionKey field in
    the SMB_COM_NEGOTIATE Response for this SMB connection.

Linux SMB client currently set this field to zero. This is working fine
against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>:

    Windows NT Server ignores the client's SessionKey.

For compatibility with [MS-CIFS], set this SessionKey field in Session
Setup Request to value retrieved from Negotiate response.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:31 +02:00
Pali Rohár
f4d483852a cifs: Remove duplicate fattr->cf_dtype assignment from wsl_to_fattr() function
[ Upstream commit 840738eae9 ]

Commit 8bd25b61c5 ("smb: client: set correct d_type for reparse DFS/DFSR
and mount point") deduplicated assignment of fattr->cf_dtype member from
all places to end of the function cifs_reparse_point_to_fattr(). The only
one missing place which was not deduplicated is wsl_to_fattr(). Fix it.

Fixes: 8bd25b61c5 ("smb: client: set correct d_type for reparse DFS/DFSR and mount point")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27 11:11:46 +01:00
Stefan Metzmacher
8ae7814589 smb: client: fix max_sge overflow in smb_extract_folioq_to_rdma()
commit a379a8a2a0 upstream.

This fixes the following problem:

[  749.901015] [   T8673] run fstests cifs/001 at 2025-06-17 09:40:30
[  750.346409] [   T9870] ==================================================================
[  750.346814] [   T9870] BUG: KASAN: slab-out-of-bounds in smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.347330] [   T9870] Write of size 8 at addr ffff888011082890 by task xfs_io/9870
[  750.347705] [   T9870]
[  750.348077] [   T9870] CPU: 0 UID: 0 PID: 9870 Comm: xfs_io Kdump: loaded Not tainted 6.16.0-rc2-metze.02+ #1 PREEMPT(voluntary)
[  750.348082] [   T9870] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  750.348085] [   T9870] Call Trace:
[  750.348086] [   T9870]  <TASK>
[  750.348088] [   T9870]  dump_stack_lvl+0x76/0xa0
[  750.348106] [   T9870]  print_report+0xd1/0x640
[  750.348116] [   T9870]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  750.348120] [   T9870]  ? kasan_complete_mode_report_info+0x26/0x210
[  750.348124] [   T9870]  kasan_report+0xe7/0x130
[  750.348128] [   T9870]  ? smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.348262] [   T9870]  ? smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.348377] [   T9870]  __asan_report_store8_noabort+0x17/0x30
[  750.348381] [   T9870]  smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.348496] [   T9870]  smbd_post_send_iter+0x1990/0x3070 [cifs]
[  750.348625] [   T9870]  ? __pfx_smbd_post_send_iter+0x10/0x10 [cifs]
[  750.348741] [   T9870]  ? update_stack_state+0x2a0/0x670
[  750.348749] [   T9870]  ? cifs_flush+0x153/0x320 [cifs]
[  750.348870] [   T9870]  ? cifs_flush+0x153/0x320 [cifs]
[  750.348990] [   T9870]  ? update_stack_state+0x2a0/0x670
[  750.348995] [   T9870]  smbd_send+0x58c/0x9c0 [cifs]
[  750.349117] [   T9870]  ? __pfx_smbd_send+0x10/0x10 [cifs]
[  750.349231] [   T9870]  ? unwind_get_return_address+0x65/0xb0
[  750.349235] [   T9870]  ? __pfx_stack_trace_consume_entry+0x10/0x10
[  750.349242] [   T9870]  ? arch_stack_walk+0xa7/0x100
[  750.349250] [   T9870]  ? stack_trace_save+0x92/0xd0
[  750.349254] [   T9870]  __smb_send_rqst+0x931/0xec0 [cifs]
[  750.349374] [   T9870]  ? kernel_text_address+0x173/0x190
[  750.349379] [   T9870]  ? kasan_save_stack+0x39/0x70
[  750.349382] [   T9870]  ? kasan_save_track+0x18/0x70
[  750.349385] [   T9870]  ? __kasan_slab_alloc+0x9d/0xa0
[  750.349389] [   T9870]  ? __pfx___smb_send_rqst+0x10/0x10 [cifs]
[  750.349508] [   T9870]  ? smb2_mid_entry_alloc+0xb4/0x7e0 [cifs]
[  750.349626] [   T9870]  ? cifs_call_async+0x277/0xb00 [cifs]
[  750.349746] [   T9870]  ? cifs_issue_write+0x256/0x610 [cifs]
[  750.349867] [   T9870]  ? netfs_do_issue_write+0xc2/0x340 [netfs]
[  750.349900] [   T9870]  ? netfs_advance_write+0x45b/0x1270 [netfs]
[  750.349929] [   T9870]  ? netfs_write_folio+0xd6c/0x1be0 [netfs]
[  750.349958] [   T9870]  ? netfs_writepages+0x2e9/0xa80 [netfs]
[  750.349987] [   T9870]  ? do_writepages+0x21f/0x590
[  750.349993] [   T9870]  ? filemap_fdatawrite_wbc+0xe1/0x140
[  750.349997] [   T9870]  ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.350002] [   T9870]  smb_send_rqst+0x22e/0x2f0 [cifs]
[  750.350131] [   T9870]  ? __pfx_smb_send_rqst+0x10/0x10 [cifs]
[  750.350255] [   T9870]  ? local_clock_noinstr+0xe/0xd0
[  750.350261] [   T9870]  ? kasan_save_alloc_info+0x37/0x60
[  750.350268] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.350271] [   T9870]  ? _raw_spin_lock+0x81/0xf0
[  750.350275] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.350278] [   T9870]  ? smb2_setup_async_request+0x293/0x580 [cifs]
[  750.350398] [   T9870]  cifs_call_async+0x477/0xb00 [cifs]
[  750.350518] [   T9870]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]
[  750.350636] [   T9870]  ? __pfx_cifs_call_async+0x10/0x10 [cifs]
[  750.350756] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.350760] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.350763] [   T9870]  ? __smb2_plain_req_init+0x933/0x1090 [cifs]
[  750.350891] [   T9870]  smb2_async_writev+0x15ff/0x2460 [cifs]
[  750.351008] [   T9870]  ? sched_clock_noinstr+0x9/0x10
[  750.351012] [   T9870]  ? local_clock_noinstr+0xe/0xd0
[  750.351018] [   T9870]  ? __pfx_smb2_async_writev+0x10/0x10 [cifs]
[  750.351144] [   T9870]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  750.351150] [   T9870]  ? _raw_spin_unlock+0xe/0x40
[  750.351154] [   T9870]  ? cifs_pick_channel+0x242/0x370 [cifs]
[  750.351275] [   T9870]  cifs_issue_write+0x256/0x610 [cifs]
[  750.351554] [   T9870]  ? cifs_issue_write+0x256/0x610 [cifs]
[  750.351677] [   T9870]  netfs_do_issue_write+0xc2/0x340 [netfs]
[  750.351710] [   T9870]  netfs_advance_write+0x45b/0x1270 [netfs]
[  750.351740] [   T9870]  ? rolling_buffer_append+0x12d/0x440 [netfs]
[  750.351769] [   T9870]  netfs_write_folio+0xd6c/0x1be0 [netfs]
[  750.351798] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.351804] [   T9870]  netfs_writepages+0x2e9/0xa80 [netfs]
[  750.351835] [   T9870]  ? __pfx_netfs_writepages+0x10/0x10 [netfs]
[  750.351864] [   T9870]  ? exit_files+0xab/0xe0
[  750.351867] [   T9870]  ? do_exit+0x148f/0x2980
[  750.351871] [   T9870]  ? do_group_exit+0xb5/0x250
[  750.351874] [   T9870]  ? arch_do_signal_or_restart+0x92/0x630
[  750.351879] [   T9870]  ? exit_to_user_mode_loop+0x98/0x170
[  750.351882] [   T9870]  ? do_syscall_64+0x2cf/0xd80
[  750.351886] [   T9870]  ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.351890] [   T9870]  do_writepages+0x21f/0x590
[  750.351894] [   T9870]  ? __pfx_do_writepages+0x10/0x10
[  750.351897] [   T9870]  filemap_fdatawrite_wbc+0xe1/0x140
[  750.351901] [   T9870]  __filemap_fdatawrite_range+0xba/0x100
[  750.351904] [   T9870]  ? __pfx___filemap_fdatawrite_range+0x10/0x10
[  750.351912] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.351916] [   T9870]  filemap_write_and_wait_range+0x7d/0xf0
[  750.351920] [   T9870]  cifs_flush+0x153/0x320 [cifs]
[  750.352042] [   T9870]  filp_flush+0x107/0x1a0
[  750.352046] [   T9870]  filp_close+0x14/0x30
[  750.352049] [   T9870]  put_files_struct.part.0+0x126/0x2a0
[  750.352053] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.352058] [   T9870]  exit_files+0xab/0xe0
[  750.352061] [   T9870]  do_exit+0x148f/0x2980
[  750.352065] [   T9870]  ? __pfx_do_exit+0x10/0x10
[  750.352069] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.352072] [   T9870]  ? _raw_spin_lock_irq+0x8a/0xf0
[  750.352076] [   T9870]  do_group_exit+0xb5/0x250
[  750.352080] [   T9870]  get_signal+0x22d3/0x22e0
[  750.352086] [   T9870]  ? __pfx_get_signal+0x10/0x10
[  750.352089] [   T9870]  ? fpregs_assert_state_consistent+0x68/0x100
[  750.352101] [   T9870]  ? folio_add_lru+0xda/0x120
[  750.352105] [   T9870]  arch_do_signal_or_restart+0x92/0x630
[  750.352109] [   T9870]  ? __pfx_arch_do_signal_or_restart+0x10/0x10
[  750.352115] [   T9870]  exit_to_user_mode_loop+0x98/0x170
[  750.352118] [   T9870]  do_syscall_64+0x2cf/0xd80
[  750.352123] [   T9870]  ? __kasan_check_read+0x11/0x20
[  750.352126] [   T9870]  ? count_memcg_events+0x1b4/0x420
[  750.352132] [   T9870]  ? handle_mm_fault+0x148/0x690
[  750.352136] [   T9870]  ? _raw_spin_lock_irq+0x8a/0xf0
[  750.352140] [   T9870]  ? __kasan_check_read+0x11/0x20
[  750.352143] [   T9870]  ? fpregs_assert_state_consistent+0x68/0x100
[  750.352146] [   T9870]  ? irqentry_exit_to_user_mode+0x2e/0x250
[  750.352151] [   T9870]  ? irqentry_exit+0x43/0x50
[  750.352154] [   T9870]  ? exc_page_fault+0x75/0xe0
[  750.352160] [   T9870]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.352163] [   T9870] RIP: 0033:0x7858c94ab6e2
[  750.352167] [   T9870] Code: Unable to access opcode bytes at 0x7858c94ab6b8.
[  750.352175] [   T9870] RSP: 002b:00007858c9248ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000022
[  750.352179] [   T9870] RAX: fffffffffffffdfe RBX: 00007858c92496c0 RCX: 00007858c94ab6e2
[  750.352182] [   T9870] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  750.352184] [   T9870] RBP: 00007858c9248d10 R08: 0000000000000000 R09: 0000000000000000
[  750.352185] [   T9870] R10: 0000000000000000 R11: 0000000000000246 R12: fffffffffffffde0
[  750.352187] [   T9870] R13: 0000000000000020 R14: 0000000000000002 R15: 00007ffc072d2230
[  750.352191] [   T9870]  </TASK>
[  750.352195] [   T9870]
[  750.395206] [   T9870] Allocated by task 9870 on cpu 0 at 750.346406s:
[  750.395523] [   T9870]  kasan_save_stack+0x39/0x70
[  750.395532] [   T9870]  kasan_save_track+0x18/0x70
[  750.395536] [   T9870]  kasan_save_alloc_info+0x37/0x60
[  750.395539] [   T9870]  __kasan_slab_alloc+0x9d/0xa0
[  750.395543] [   T9870]  kmem_cache_alloc_noprof+0x13c/0x3f0
[  750.395548] [   T9870]  mempool_alloc_slab+0x15/0x20
[  750.395553] [   T9870]  mempool_alloc_noprof+0x135/0x340
[  750.395557] [   T9870]  smbd_post_send_iter+0x63e/0x3070 [cifs]
[  750.395694] [   T9870]  smbd_send+0x58c/0x9c0 [cifs]
[  750.395819] [   T9870]  __smb_send_rqst+0x931/0xec0 [cifs]
[  750.395950] [   T9870]  smb_send_rqst+0x22e/0x2f0 [cifs]
[  750.396081] [   T9870]  cifs_call_async+0x477/0xb00 [cifs]
[  750.396232] [   T9870]  smb2_async_writev+0x15ff/0x2460 [cifs]
[  750.396359] [   T9870]  cifs_issue_write+0x256/0x610 [cifs]
[  750.396492] [   T9870]  netfs_do_issue_write+0xc2/0x340 [netfs]
[  750.396544] [   T9870]  netfs_advance_write+0x45b/0x1270 [netfs]
[  750.396576] [   T9870]  netfs_write_folio+0xd6c/0x1be0 [netfs]
[  750.396608] [   T9870]  netfs_writepages+0x2e9/0xa80 [netfs]
[  750.396639] [   T9870]  do_writepages+0x21f/0x590
[  750.396643] [   T9870]  filemap_fdatawrite_wbc+0xe1/0x140
[  750.396647] [   T9870]  __filemap_fdatawrite_range+0xba/0x100
[  750.396651] [   T9870]  filemap_write_and_wait_range+0x7d/0xf0
[  750.396656] [   T9870]  cifs_flush+0x153/0x320 [cifs]
[  750.396787] [   T9870]  filp_flush+0x107/0x1a0
[  750.396791] [   T9870]  filp_close+0x14/0x30
[  750.396795] [   T9870]  put_files_struct.part.0+0x126/0x2a0
[  750.396800] [   T9870]  exit_files+0xab/0xe0
[  750.396803] [   T9870]  do_exit+0x148f/0x2980
[  750.396808] [   T9870]  do_group_exit+0xb5/0x250
[  750.396813] [   T9870]  get_signal+0x22d3/0x22e0
[  750.396817] [   T9870]  arch_do_signal_or_restart+0x92/0x630
[  750.396822] [   T9870]  exit_to_user_mode_loop+0x98/0x170
[  750.396827] [   T9870]  do_syscall_64+0x2cf/0xd80
[  750.396832] [   T9870]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.396836] [   T9870]
[  750.397150] [   T9870] The buggy address belongs to the object at ffff888011082800
                           which belongs to the cache smbd_request_0000000008f3bd7b of size 144
[  750.397798] [   T9870] The buggy address is located 0 bytes to the right of
                           allocated 144-byte region [ffff888011082800, ffff888011082890)
[  750.398469] [   T9870]
[  750.398800] [   T9870] The buggy address belongs to the physical page:
[  750.399141] [   T9870] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11082
[  750.399148] [   T9870] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
[  750.399155] [   T9870] page_type: f5(slab)
[  750.399161] [   T9870] raw: 000fffffc0000000 ffff888022d65640 dead000000000122 0000000000000000
[  750.399165] [   T9870] raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
[  750.399169] [   T9870] page dumped because: kasan: bad access detected
[  750.399172] [   T9870]
[  750.399505] [   T9870] Memory state around the buggy address:
[  750.399863] [   T9870]  ffff888011082780: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  750.400247] [   T9870]  ffff888011082800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  750.400618] [   T9870] >ffff888011082880: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  750.400982] [   T9870]                          ^
[  750.401370] [   T9870]  ffff888011082900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  750.401774] [   T9870]  ffff888011082980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  750.402171] [   T9870] ==================================================================
[  750.402696] [   T9870] Disabling lock debugging due to kernel taint
[  750.403202] [   T9870] BUG: unable to handle page fault for address: ffff8880110a2000
[  750.403797] [   T9870] #PF: supervisor write access in kernel mode
[  750.404204] [   T9870] #PF: error_code(0x0003) - permissions violation
[  750.404581] [   T9870] PGD 5ce01067 P4D 5ce01067 PUD 5ce02067 PMD 78aa063 PTE 80000000110a2021
[  750.404969] [   T9870] Oops: Oops: 0003 [#1] SMP KASAN PTI
[  750.405394] [   T9870] CPU: 0 UID: 0 PID: 9870 Comm: xfs_io Kdump: loaded Tainted: G    B               6.16.0-rc2-metze.02+ #1 PREEMPT(voluntary)
[  750.406510] [   T9870] Tainted: [B]=BAD_PAGE
[  750.406967] [   T9870] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  750.407440] [   T9870] RIP: 0010:smb_set_sge+0x15c/0x3b0 [cifs]
[  750.408065] [   T9870] Code: 48 83 f8 ff 0f 84 b0 00 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 e1 48 c1 e9 03 80 3c 11 00 0f 85 69 01 00 00 49 8d 7c 24 08 <49> 89 04 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f
[  750.409283] [   T9870] RSP: 0018:ffffc90005e2e758 EFLAGS: 00010246
[  750.409803] [   T9870] RAX: ffff888036c53400 RBX: ffffc90005e2e878 RCX: 1ffff11002214400
[  750.410323] [   T9870] RDX: dffffc0000000000 RSI: dffffc0000000000 RDI: ffff8880110a2008
[  750.411217] [   T9870] RBP: ffffc90005e2e798 R08: 0000000000000001 R09: 0000000000000400
[  750.411770] [   T9870] R10: ffff888011082800 R11: 0000000000000000 R12: ffff8880110a2000
[  750.412325] [   T9870] R13: 0000000000000000 R14: ffffc90005e2e888 R15: ffff88801a4b6000
[  750.412901] [   T9870] FS:  0000000000000000(0000) GS:ffff88812bc68000(0000) knlGS:0000000000000000
[  750.413477] [   T9870] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  750.414077] [   T9870] CR2: ffff8880110a2000 CR3: 000000005b0a6005 CR4: 00000000000726f0
[  750.414654] [   T9870] Call Trace:
[  750.415211] [   T9870]  <TASK>
[  750.415748] [   T9870]  smbd_post_send_iter+0x1990/0x3070 [cifs]
[  750.416449] [   T9870]  ? __pfx_smbd_post_send_iter+0x10/0x10 [cifs]
[  750.417128] [   T9870]  ? update_stack_state+0x2a0/0x670
[  750.417685] [   T9870]  ? cifs_flush+0x153/0x320 [cifs]
[  750.418380] [   T9870]  ? cifs_flush+0x153/0x320 [cifs]
[  750.419055] [   T9870]  ? update_stack_state+0x2a0/0x670
[  750.419624] [   T9870]  smbd_send+0x58c/0x9c0 [cifs]
[  750.420297] [   T9870]  ? __pfx_smbd_send+0x10/0x10 [cifs]
[  750.420936] [   T9870]  ? unwind_get_return_address+0x65/0xb0
[  750.421456] [   T9870]  ? __pfx_stack_trace_consume_entry+0x10/0x10
[  750.421954] [   T9870]  ? arch_stack_walk+0xa7/0x100
[  750.422460] [   T9870]  ? stack_trace_save+0x92/0xd0
[  750.422948] [   T9870]  __smb_send_rqst+0x931/0xec0 [cifs]
[  750.423579] [   T9870]  ? kernel_text_address+0x173/0x190
[  750.424056] [   T9870]  ? kasan_save_stack+0x39/0x70
[  750.424813] [   T9870]  ? kasan_save_track+0x18/0x70
[  750.425323] [   T9870]  ? __kasan_slab_alloc+0x9d/0xa0
[  750.425831] [   T9870]  ? __pfx___smb_send_rqst+0x10/0x10 [cifs]
[  750.426548] [   T9870]  ? smb2_mid_entry_alloc+0xb4/0x7e0 [cifs]
[  750.427231] [   T9870]  ? cifs_call_async+0x277/0xb00 [cifs]
[  750.427882] [   T9870]  ? cifs_issue_write+0x256/0x610 [cifs]
[  750.428909] [   T9870]  ? netfs_do_issue_write+0xc2/0x340 [netfs]
[  750.429425] [   T9870]  ? netfs_advance_write+0x45b/0x1270 [netfs]
[  750.429882] [   T9870]  ? netfs_write_folio+0xd6c/0x1be0 [netfs]
[  750.430345] [   T9870]  ? netfs_writepages+0x2e9/0xa80 [netfs]
[  750.430809] [   T9870]  ? do_writepages+0x21f/0x590
[  750.431239] [   T9870]  ? filemap_fdatawrite_wbc+0xe1/0x140
[  750.431652] [   T9870]  ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.432041] [   T9870]  smb_send_rqst+0x22e/0x2f0 [cifs]
[  750.432586] [   T9870]  ? __pfx_smb_send_rqst+0x10/0x10 [cifs]
[  750.433108] [   T9870]  ? local_clock_noinstr+0xe/0xd0
[  750.433482] [   T9870]  ? kasan_save_alloc_info+0x37/0x60
[  750.433855] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.434214] [   T9870]  ? _raw_spin_lock+0x81/0xf0
[  750.434561] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.434903] [   T9870]  ? smb2_setup_async_request+0x293/0x580 [cifs]
[  750.435394] [   T9870]  cifs_call_async+0x477/0xb00 [cifs]
[  750.435892] [   T9870]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]
[  750.436388] [   T9870]  ? __pfx_cifs_call_async+0x10/0x10 [cifs]
[  750.436881] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.437237] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.437579] [   T9870]  ? __smb2_plain_req_init+0x933/0x1090 [cifs]
[  750.438062] [   T9870]  smb2_async_writev+0x15ff/0x2460 [cifs]
[  750.438557] [   T9870]  ? sched_clock_noinstr+0x9/0x10
[  750.438906] [   T9870]  ? local_clock_noinstr+0xe/0xd0
[  750.439293] [   T9870]  ? __pfx_smb2_async_writev+0x10/0x10 [cifs]
[  750.439786] [   T9870]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  750.440143] [   T9870]  ? _raw_spin_unlock+0xe/0x40
[  750.440495] [   T9870]  ? cifs_pick_channel+0x242/0x370 [cifs]
[  750.440989] [   T9870]  cifs_issue_write+0x256/0x610 [cifs]
[  750.441492] [   T9870]  ? cifs_issue_write+0x256/0x610 [cifs]
[  750.441987] [   T9870]  netfs_do_issue_write+0xc2/0x340 [netfs]
[  750.442387] [   T9870]  netfs_advance_write+0x45b/0x1270 [netfs]
[  750.442969] [   T9870]  ? rolling_buffer_append+0x12d/0x440 [netfs]
[  750.443376] [   T9870]  netfs_write_folio+0xd6c/0x1be0 [netfs]
[  750.443768] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.444145] [   T9870]  netfs_writepages+0x2e9/0xa80 [netfs]
[  750.444541] [   T9870]  ? __pfx_netfs_writepages+0x10/0x10 [netfs]
[  750.444936] [   T9870]  ? exit_files+0xab/0xe0
[  750.445312] [   T9870]  ? do_exit+0x148f/0x2980
[  750.445672] [   T9870]  ? do_group_exit+0xb5/0x250
[  750.446028] [   T9870]  ? arch_do_signal_or_restart+0x92/0x630
[  750.446402] [   T9870]  ? exit_to_user_mode_loop+0x98/0x170
[  750.446762] [   T9870]  ? do_syscall_64+0x2cf/0xd80
[  750.447132] [   T9870]  ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.447499] [   T9870]  do_writepages+0x21f/0x590
[  750.447859] [   T9870]  ? __pfx_do_writepages+0x10/0x10
[  750.448236] [   T9870]  filemap_fdatawrite_wbc+0xe1/0x140
[  750.448595] [   T9870]  __filemap_fdatawrite_range+0xba/0x100
[  750.448953] [   T9870]  ? __pfx___filemap_fdatawrite_range+0x10/0x10
[  750.449336] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.449697] [   T9870]  filemap_write_and_wait_range+0x7d/0xf0
[  750.450062] [   T9870]  cifs_flush+0x153/0x320 [cifs]
[  750.450592] [   T9870]  filp_flush+0x107/0x1a0
[  750.450952] [   T9870]  filp_close+0x14/0x30
[  750.451322] [   T9870]  put_files_struct.part.0+0x126/0x2a0
[  750.451678] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.452033] [   T9870]  exit_files+0xab/0xe0
[  750.452401] [   T9870]  do_exit+0x148f/0x2980
[  750.452751] [   T9870]  ? __pfx_do_exit+0x10/0x10
[  750.453109] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.453459] [   T9870]  ? _raw_spin_lock_irq+0x8a/0xf0
[  750.453787] [   T9870]  do_group_exit+0xb5/0x250
[  750.454082] [   T9870]  get_signal+0x22d3/0x22e0
[  750.454406] [   T9870]  ? __pfx_get_signal+0x10/0x10
[  750.454709] [   T9870]  ? fpregs_assert_state_consistent+0x68/0x100
[  750.455031] [   T9870]  ? folio_add_lru+0xda/0x120
[  750.455347] [   T9870]  arch_do_signal_or_restart+0x92/0x630
[  750.455656] [   T9870]  ? __pfx_arch_do_signal_or_restart+0x10/0x10
[  750.455967] [   T9870]  exit_to_user_mode_loop+0x98/0x170
[  750.456282] [   T9870]  do_syscall_64+0x2cf/0xd80
[  750.456591] [   T9870]  ? __kasan_check_read+0x11/0x20
[  750.456897] [   T9870]  ? count_memcg_events+0x1b4/0x420
[  750.457280] [   T9870]  ? handle_mm_fault+0x148/0x690
[  750.457616] [   T9870]  ? _raw_spin_lock_irq+0x8a/0xf0
[  750.457925] [   T9870]  ? __kasan_check_read+0x11/0x20
[  750.458297] [   T9870]  ? fpregs_assert_state_consistent+0x68/0x100
[  750.458672] [   T9870]  ? irqentry_exit_to_user_mode+0x2e/0x250
[  750.459191] [   T9870]  ? irqentry_exit+0x43/0x50
[  750.459600] [   T9870]  ? exc_page_fault+0x75/0xe0
[  750.460130] [   T9870]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.460570] [   T9870] RIP: 0033:0x7858c94ab6e2
[  750.461206] [   T9870] Code: Unable to access opcode bytes at 0x7858c94ab6b8.
[  750.461780] [   T9870] RSP: 002b:00007858c9248ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000022
[  750.462327] [   T9870] RAX: fffffffffffffdfe RBX: 00007858c92496c0 RCX: 00007858c94ab6e2
[  750.462653] [   T9870] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  750.462969] [   T9870] RBP: 00007858c9248d10 R08: 0000000000000000 R09: 0000000000000000
[  750.463290] [   T9870] R10: 0000000000000000 R11: 0000000000000246 R12: fffffffffffffde0
[  750.463640] [   T9870] R13: 0000000000000020 R14: 0000000000000002 R15: 00007ffc072d2230
[  750.463965] [   T9870]  </TASK>
[  750.464285] [   T9870] Modules linked in: siw ib_uverbs ccm cmac nls_utf8 cifs cifs_arc4 nls_ucs2_utils rdma_cm iw_cm ib_cm ib_core cifs_md4 netfs softdog vboxsf vboxguest cpuid intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_class intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel sha1_ssse3 aesni_intel rapl i2c_piix4 i2c_smbus joydev input_leds mac_hid sunrpc binfmt_misc kvm_intel kvm irqbypass sch_fq_codel efi_pstore nfnetlink vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock vmw_vmci dmi_sysfs ip_tables x_tables autofs4 hid_generic vboxvideo usbhid drm_vram_helper psmouse vga16fb vgastate drm_ttm_helper serio_raw hid ahci libahci ttm pata_acpi video wmi [last unloaded: vboxguest]
[  750.467127] [   T9870] CR2: ffff8880110a2000

cc: Tom Talpey <tom@talpey.com>
cc: linux-cifs@vger.kernel.org
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Fixes: c45ebd636c ("cifs: Provide the capability to extract from ITER_FOLIOQ to RDMA SGEs")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:45 +01:00
zhangjian
e27cb3ac5a smb: client: fix first command failure during re-negotiation
commit 34331d7bee upstream.

after fabc4ed200, server_unresponsive add a condition to check whether client
need to reconnect depending on server->lstrp. When client failed to reconnect
for some time and abort connection, server->lstrp is updated for the last time.
In the following scene, server->lstrp is too old. This cause next command
failure in re-negotiation rather than waiting for re-negotiation done.

1. mount -t cifs -o username=Everyone,echo_internal=10 //$server_ip/export /mnt
2. ssh $server_ip "echo b > /proc/sysrq-trigger &"
3. ls /mnt
4. sleep 21s
5. ssh $server_ip "service firewalld stop"
6. ls # return EHOSTDOWN

If the interval between 5 and 6 is too small, 6 may trigger sending negotiation
request. Before backgrounding cifsd thread try to receive negotiation response
from server in cifs_readv_from_socket, server_unresponsive may trigger
cifs_reconnect which cause 6 to be failed:

ls thread
----------------
  smb2_negotiate
    server->tcpStatus = CifsInNegotiate
    compound_send_recv
      wait_for_compound_request

cifsd thread
----------------
  cifs_readv_from_socket
    server_unresponsive
      server->tcpStatus == CifsInNegotiate && jiffies > server->lstrp + 20s
        cifs_reconnect
          cifs_abort_connection: mid_state = MID_RETRY_NEEDED

ls thread
----------------
      cifs_sync_mid_result return EAGAIN
  smb2_negotiate return EHOSTDOWN

Though server->lstrp means last server response time, it is updated in
cifs_abort_connection and cifs_get_tcp_session. We can also update server->lstrp
before switching into CifsInNegotiate state to avoid failure in 6.

Fixes: 7ccc146546 ("smb: client: fix hang in wait_for_response() for negproto")
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Acked-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: zhangjian <zhangjian496@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:45 +01:00
Paul Aurich
43f26094d6 smb: Log an error when close_all_cached_dirs fails
commit a2182743a8 upstream.

Under low-memory conditions, close_all_cached_dirs() can't move the
dentries to a separate list to dput() them once the locks are dropped.
This will result in a "Dentry still in use" error, so add an error
message that makes it clear this is what happened:

[  495.281119] CIFS: VFS: \\otters.example.com\share Out of memory while dropping dentries
[  495.281595] ------------[ cut here ]------------
[  495.281887] BUG: Dentry ffff888115531138{i=78,n=/}  still in use (2) [unmount of cifs cifs]
[  495.282391] WARNING: CPU: 1 PID: 2329 at fs/dcache.c:1536 umount_check+0xc8/0xf0

Also, bail out of looping through all tcons as soon as a single
allocation fails, since we're already in trouble, and kmalloc() attempts
for subseqeuent tcons are likely to fail just like the first one did.

Signed-off-by: Paul Aurich <paul@darkrain42.org>
Acked-by: Bharath SM <bharathsm@microsoft.com>
Suggested-by: Ruben Devos <rdevos@oxya.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:45 +01:00
Bharath SM
9411a9909e smb: fix secondary channel creation issue with kerberos by populating hostname when adding channels
commit 306cb65bb0 upstream.

When mounting a share with kerberos authentication with multichannel
support, share mounts correctly, but fails to create secondary
channels. This occurs because the hostname is not populated when
adding the channels. The hostname is necessary for the userspace
cifs.upcall program to retrieve the required credentials and pass
it back to kernel, without hostname secondary channels fails
establish.

Cc: stable@vger.kernel.org
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Reported-by: xfuren <xfuren@gmail.com>
Link: https://bugzilla.samba.org/show_bug.cgi?id=15824
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27 11:11:41 +01:00
Bharath SM
3a83a904bf smb: improve directory cache reuse for readdir operations
commit 72dd7961a4 upstream.

Currently, cached directory contents were not reused across subsequent
'ls' operations because the cache validity check relied on comparing
the ctx pointer, which changes with each readdir invocation. As a
result, the cached dir entries was not marked as valid and the cache was
not utilized for subsequent 'ls' operations.

This change uses the file pointer, which remains consistent across all
readdir calls for a given directory instance, to associate and validate
the cache. As a result, cached directory contents can now be
correctly reused, improving performance for repeated directory listings.

Performance gains with local windows SMB server:

Without the patch and default actimeo=1:
 1000 directory enumeration operations on dir with 10k files took 135.0s

With this patch and actimeo=0:
 1000 directory enumeration operations on dir with 10k files took just 5.1s

Signed-off-by: Bharath SM <bharathsm@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>
2025-06-27 11:11:37 +01:00
Shyam Prasad N
2c34f1e095 cifs: do not disable interface polling on failure
commit 42ca547b13 upstream.

When a server has multichannel enabled, we keep polling the server
for interfaces periodically. However, when this query fails, we
disable the polling. This can be problematic as it takes away the
chance for the server to start advertizing again.

This change reschedules the delayed work, even if the current call
failed. That way, multichannel sessions can recover.

Signed-off-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>
2025-06-27 11:11:37 +01:00
Shyam Prasad N
3b2bec886f cifs: serialize other channels when query server interfaces is pending
commit b5e3e6e28c upstream.

Today, during smb2_reconnect, session_mutex is released as soon as
the tcon is reconnected and is in a good state. However, in case
multichannel is enabled, there is also a query of server interfaces that
follows. We've seen that this query can race with reconnects of other
channels, causing them to step on each other with reconnects.

This change extends the hold of session_mutex till after the query of
server interfaces is complete. In order to avoid recursive smb2_reconnect
checks during query ioctl, this change also introduces a session flag
for sessions where such a query is in progress.

Signed-off-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>
2025-06-27 11:11:37 +01:00
Shyam Prasad N
b735c8dfbf cifs: deal with the channel loading lag while picking channels
commit 66d590b828 upstream.

Our current approach to select a channel for sending requests is this:
1. iterate all channels to find the min and max queue depth
2. if min and max are not the same, pick the channel with min depth
3. if min and max are same, round robin, as all channels are equally loaded

The problem with this approach is that there's a lag between selecting
a channel and sending the request (that increases the queue depth on the channel).
While these numbers will eventually catch up, there could be a skew in the
channel usage, depending on the application's I/O parallelism and the server's
speed of handling requests.

With sufficient parallelism, this lag can artificially increase the queue depth,
thereby impacting the performance negatively.

This change will change the step 1 above to start the iteration from the last
selected channel. This is to reduce the skew in channel usage even in the presence
of this lag.

Fixes: ea90708d3c ("cifs: use the least loaded channel for sending requests")
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>
2025-06-27 11:11:37 +01:00