CVE-2025-38352
posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()
Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
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.
CISA notes
This vulnerability affects a common open-source component, third-party library, or a protocol used by different products. Please check with specific vendors for information on patching status. For more information, please see: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff ; https://source.android.com/docs/security/bulletin/2025-09-01 ; https://nvd.nist.gov/vuln/detail/CVE-2025-38352
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.
Severity
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HAffected Products
| Vendor | Product | Affected versions |
|---|---|---|
| Linux | Linux | 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <78a4b8e3795b31dae58762bc091bb0f4f74a2200 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <c076635b3a42771ace7d276de8dc3bc76ee2ba1b 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <2f3daa04a9328220de46f0d5c919a6c0073a9f0b 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <764a7a5dfda23f69919441f2eac2a83e7db6e5bb 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <c29d5318708e67ac13c1b6fc1007d179fb65b4d7 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <460188bc042a3f40f72d34b9f7fc6ee66b0b757b 0bdd2ed4138ec04e09b4f8165981efc99e439f55 to <f90fff1e152dedf52b932240ebbd670d83330eca |
| Linux | Linux | 2.6.36 0 to <2.6.36 (unaffected) 5.4.295 to 5.4.* (unaffected) 5.10.239 to 5.10.* (unaffected) 5.15.186 to 5.15.* (unaffected) 6.1.142 to 6.1.* (unaffected) 6.6.94 to 6.6.* (unaffected) 6.12.34 to 6.12.* (unaffected) 6.15.3 to 6.15.* (unaffected) 6.16 to * (unaffected) |
References
10 Links- https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200
- https://git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b
- https://git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b
- https://git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb
- https://git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff
- https://git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7
- https://git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b
- https://git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
Record Details
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