CVE-2025-38352
Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Linux, fix it now.
CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
US federal civilian agencies must remediate by Sep 25, 2025.
Patch status
Official fix available since
Apply the vendor's update to every affected system. Check the fixed-in versions below where known.
Basis: NVD patch reference
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
- Patch or advisory on git.kernel.org (opens in a new tab)
Description
In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del() If an exiting non-autoreaping task has already passed exit_notify() and calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent or debugger right after unlock_task_sighand(). If a concurrent posix_cpu_timer_del() runs at that moment, it won't be able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or lock_task_sighand() will fail. Add the tsk->exit_state check into run_posix_cpu_timers() to fix this. This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because exit_task_work() is called before exit_notify(). But the check still makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail anyway in this case.
Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.
Affected products
| Product | Vendor | Affected versions | Fixed in | Source |
|---|---|---|---|---|
| Linux | Linux | >= 2.6.36, < 5.4.295; >= 5.5, < 5.10.239; >= 5.11, < 5.15.186; >= 5.16, < 6.1.142; >= 6.2, < 6.6.94; >= 6.7, < 6.12.34 | 5.4.295; 5.10.239; 5.15.186; 6.1.142; 6.6.94; 6.12.34 | KEV |
Sources: KEV = CISA Known Exploited Vulnerabilities catalog.
Intelligence timeline
Developments from the last 30 days, newest first.
- CVSS scoredUpdateKEV
CVE-2025-38352 scored CVSS 7.8: Linux Kernel, Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability
CISA lists this as exploited in the wild. Unpatched Kernel systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
- Patch releasedUpdateKEV
Patch released for CVE-2025-38352: Linux Kernel, Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability
An official fix is now available for Linux Kernel. This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference
1 earlier event is available with a subscription. See plans.
Coverage
We have not published a story about this vulnerability yet.