In the Linux kernel, the following vulnerability has been resolved:
ptp: remove ptp->n_vclocks check logic in ptp_vclock_in_use()
There is no disagreement that we should check both ptp->is_virtual_clock
and ptp->n_vclocks to check if the ptp virtual clock is in use.
However, when we acquire ptp->n_vclocks_mux to read ptp->n_vclocks in
ptp_vclock_in_use(), we observe a recursive lock in the call trace
starting from n_vclocks_store().
============================================
WARNING: possible recursive locking detected
6.15.0-rc6 #1 Not tainted
--------------------------------------------
syz.0.1540/13807 is trying to acquire lock:
ffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at:
ptp_vclock_in_use drivers/ptp/ptp_private.h:103 [inline]
ffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at:
ptp_clock_unregister+0x21/0x250 drivers/ptp/ptp_clock.c:415
but task is already holding lock:
ffff888030704868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at:
n_vclocks_store+0xf1/0x6d0 drivers/ptp/ptp_sysfs.c:215
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ptp->n_vclocks_mux);
lock(&ptp->n_vclocks_mux);
*** DEADLOCK ***
....
============================================
The best way to solve this is to remove the logic that checks
ptp->n_vclocks in ptp_vclock_in_use().
The reason why this is appropriate is that any path that uses
ptp->n_vclocks must unconditionally check if ptp->n_vclocks is greater
than 0 before unregistering vclocks, and all functions are already
written this way. And in the function that uses ptp->n_vclocks, we
already get ptp->n_vclocks_mux before unregistering vclocks.
Therefore, we need to remove the redundant check for ptp->n_vclocks in
ptp_vclock_in_use() to prevent recursive locking.
References
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
|
History
19 Dec 2025, 17:58
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux
Debian Debian debian Linux Linux linux Kernel |
|
| References | () https://git.kernel.org/stable/c/259119595227fd20f6aa29d85abe086b6fdd9eb1 - Patch | |
| References | () https://git.kernel.org/stable/c/5d217e7031a5c06d366580fc6ddbf43527b780d4 - Patch | |
| References | () https://git.kernel.org/stable/c/87f7ce260a3c838b49e1dc1ceedf1006795157a2 - Patch | |
| References | () https://git.kernel.org/stable/c/b1b73c452331451020be3bf4b014901015ae6663 - Patch | |
| References | () https://git.kernel.org/stable/c/b93e6fef4eda48e17d9c642b9abad98a066fd4a3 - Patch | |
| References | () https://git.kernel.org/stable/c/ef8fc007c28a30a4c0d90bf755e0f343d99bb392 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory | |
| CWE | NVD-CWE-noinfo | |
| CPE | cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc7:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:* |
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
10 Jul 2025, 13:17
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
10 Jul 2025, 08:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-07-10 08:15
Updated : 2025-12-19 17:58
NVD link : CVE-2025-38305
Mitre link : CVE-2025-38305
CVE.ORG link : CVE-2025-38305
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE