CVE-2025-39859: Linux kernel · ptp: ocp: fix use-after-free bugs causing by ptp_ocp_watchdog
Source GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in f10d3c7267ac7387a5129d5506c3c5f2460cfd9b : patch Linux kernel soon.
Data as of 30 Oct 2026, 16:33 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 7.8 |
|---|
- Patch
- Available – fixed in f10d3c7267ac7387a5129d5506c3c5f2460cfd9b, e2a6eabe5304a789b7d40ce2576cd80154255e51, aad70bdfc8244616e48c434310cab241a3f17781 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
Description
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.
References
- nvd.nist.gov/vuln/detail/CVE-2025-39859 (opens in a new tab)
- git.kernel.org/stable/c/8bf935cf789872350b04c1a6468b0a509f67afb2 (opens in a new tab)
- git.kernel.org/stable/c/a59822a762039b6e0252f21b091245d6ad7f324b (opens in a new tab)
- git.kernel.org/stable/c/aad70bdfc8244616e48c434310cab241a3f17781 (opens in a new tab)
- git.kernel.org/stable/c/e2a6eabe5304a789b7d40ce2576cd80154255e51 (opens in a new tab)
- git.kernel.org/stable/c/f10d3c7267ac7387a5129d5506c3c5f2460cfd9b (opens in a new tab)