cifs: Fix UAF in cifs_demultiplex_thread()
There is a UAF when xfstests on cifs:
BUG: KASAN: use-after-free in smb2_is_network_name_deleted+0x27/0x160
Read of size 4 at addr ffff88810103fc08 by task cifsd/923
CPU: 1 PID: 923 Comm: cifsd Not tainted 6.1.0-rc4+ #45
...
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report+0x171/0x472
kasan_report+0xad/0x130
kasan_check_range+0x145/0x1a0
smb2_is_network_name_deleted+0x27/0x160
cifs_demultiplex_thread.cold+0x172/0x5a4
kthread+0x165/0x1a0
ret_from_fork+0x1f/0x30
</TASK>
Allocated by task 923:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_slab_alloc+0x54/0x60
kmem_cache_alloc+0x147/0x320
mempool_alloc+0xe1/0x260
cifs_small_buf_get+0x24/0x60
allocate_buffers+0xa1/0x1c0
cifs_demultiplex_thread+0x199/0x10d0
kthread+0x165/0x1a0
ret_from_fork+0x1f/0x30
Freed by task 921:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x40
____kasan_slab_free+0x143/0x1b0
kmem_cache_free+0xe3/0x4d0
cifs_small_buf_release+0x29/0x90
SMB2_negotiate+0x8b7/0x1c60
smb2_negotiate+0x51/0x70
cifs_negotiate_protocol+0xf0/0x160
cifs_get_smb_ses+0x5fa/0x13c0
mount_get_conns+0x7a/0x750
cifs_mount+0x103/0xd00
cifs_smb3_do_mount+0x1dd/0xcb0
smb3_get_tree+0x1d5/0x300
vfs_get_tree+0x41/0xf0
path_mount+0x9b3/0xdd0
__x64_sys_mount+0x190/0x1d0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
The UAF is because:
mount(pid: 921) | cifsd(pid: 923)
-------------------------------|-------------------------------
| cifs_demultiplex_thread
SMB2_negotiate |
cifs_send_recv |
compound_send_recv |
smb_send_rqst |
wait_for_response |
wait_event_state [1] |
| standard_receive3
| cifs_handle_standard
| handle_mid
| mid->resp_buf = buf; [2]
| dequeue_mid [3]
KILL the process [4] |
resp_iov[i].iov_base = buf |
free_rsp_buf [5] |
| is_network_name_deleted [6]
| callback
1. After send request to server, wait the response until
mid->mid_state != SUBMITTED;
2. Receive response from server, and set it to mid;
3. Set the mid state to RECEIVED;
4. Kill the process, the mid state already RECEIVED, get 0;
5. Handle and release the negotiate response;
6. UAF.
It can be easily reproduce with add some delay in [3] - [6].
Only sync call has the problem since async call's callback is
executed in cifsd process.
Add an extra state to mark the mid state to READY before wakeup the
waitter, then it can get the resp safely.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4178-1 | linux security update |
Ubuntu USN |
USN-7123-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7194-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7654-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7654-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7654-3 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-7654-4 | Linux kernel (KVM) vulnerabilities |
Ubuntu USN |
USN-7654-5 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7655-1 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-7686-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 03 Nov 2025 20:30:00 +0000
| Type | Values Removed | Values Added |
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| References |
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Thu, 28 Aug 2025 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Fri, 02 May 2025 06:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Wed, 11 Dec 2024 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-416 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.6:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.6:rc2:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Mon, 04 Nov 2024 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 17 Sep 2024 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
threat_severity
|
threat_severity
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T19:28:45.115Z
Reserved: 2024-03-02T21:55:42.567Z
Link: CVE-2023-52572
Updated: 2025-11-03T19:28:45.115Z
Status : Modified
Published: 2024-03-02T22:15:49.300
Modified: 2025-11-03T20:16:05.190
Link: CVE-2023-52572
OpenCVE Enrichment
No data.
Debian DLA
Ubuntu USN