CVE-2025-39859
HIGHCVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
3Description
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.
Analysis
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. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.
Technical Context
This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. 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. Affected products include: Linux Linux Kernel.
Affected Products
Linux Linux Kernel.
Remediation
A vendor patch is available. Apply the latest security update as soon as possible. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.
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