CVE-2025-39859

In the Linux kernel, the following vulnerability has been resolved: ptp: ocp: fix use-after-free bugs causing by ptp_ocp_watchdog The ptp_ocp_detach() only shuts down the watchdog timer if it is pending. However, if the timer handler is already running, the timer_delete_sync() is not called. This leads to race conditions where the devlink that contains the ptp_ocp is deallocated while the timer handler is still accessing it, resulting in use-after-free bugs. The following details one of the race scenarios. (thread 1) | (thread 2) ptp_ocp_remove() | ptp_ocp_detach() | ptp_ocp_watchdog() if (timer_pending(&bp->watchdog))| bp = timer_container_of() timer_delete_sync() | | devlink_free(devlink) //free | | bp-> //use Resolve this by unconditionally calling timer_delete_sync() to ensure the timer is reliably deactivated, preventing any access after free.

CVSS 3.1

7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 9% of CVEs (scores of 2026-10-25)

CWE

CWE-416

Published

2025-09-19

Modified

2026-10-21

Record from

the NVD, synced 2026-10-22

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/8bf935cf789872350b04c1a6468b0a509f67afb2
• https://git.kernel.org/stable/c/aad70bdfc8244616e48c434310cab241a3f17781
• https://git.kernel.org/stable/c/e2a6eabe5304a789b7d40ce2576cd80154255e51
• https://git.kernel.org/stable/c/f10d3c7267ac7387a5129d5506c3c5f2460cfd9b

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