Use After Free Affecting linux-azure-6.12 package, versions <6.12.80-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.2% (10th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-LINUXAZURE612-15991950
  • published12 Apr 2026
  • disclosed19 Sept 2025

Introduced: 19 Sep 2025

CVE-2025-39859  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Chainguard linux-azure-6.12 to version 6.12.80-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-azure-6.12 package and not the linux-azure-6.12 package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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 Base Scores

version 3.1