In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix potential deadlock when reconnecting channels
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
References
Configurations
Configuration 1 (hide)
|
History
20 Nov 2025, 20:13
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/711741f94ac3cf9f4e3aa73aa171e76d188c0819 - Patch | |
| References | () https://git.kernel.org/stable/c/7f3ead8ebc0ef65b6c89a13912b4e80218425629 - Patch | |
| References | () https://git.kernel.org/stable/c/c82c7041258d96e3286f6790ab700e4edd3cc9e3 - Patch | |
| References | () https://git.kernel.org/stable/c/fe035dc78aa6ca8f862857d45beaf7a0e03206ca - Patch | |
| CWE | CWE-667 | |
| CPE | cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux
Linux linux Kernel |
10 Jul 2025, 13:17
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
09 Jul 2025, 11:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-07-09 11:15
Updated : 2025-11-20 20:13
NVD link : CVE-2025-38244
Mitre link : CVE-2025-38244
CVE.ORG link : CVE-2025-38244
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-667
Improper Locking
