CVE-2025-38352

posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()

High 7.8
Exploited: added to CISA KEV 4 Sep 2025

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.

Key facts

Published: 22 Jul 2025
Last changed: 8 Sep 2026
Assigned by: Linux
KEV added: 4 Sep 2025
KEV fix due: 25 Sep 2025
EPSS: 1.357% likely to be exploited in the next 30 days, higher than 72.125% of CVEs (scores for 15 Nov 2026)
SSVC (CISA): Exploitation: active; Automatable: no; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

7.8CVSS 3.1, Highfrom the CNA (Linux)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What to do

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 KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Vendor	Product	Versions
Linux	Linux	Default status: unaffected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding 78a4b8e3795b31dae58762bc091bb0f4f74a2200 (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding c076635b3a42771ace7d276de8dc3bc76ee2ba1b (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding 2f3daa04a9328220de46f0d5c919a6c0073a9f0b (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding 764a7a5dfda23f69919441f2eac2a83e7db6e5bb (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding c29d5318708e67ac13c1b6fc1007d179fb65b4d7 (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding 460188bc042a3f40f72d34b9f7fc6ee66b0b757b (affected) 0bdd2ed4138ec04e09b4f8165981efc99e439f55 up to but excluding f90fff1e152dedf52b932240ebbd670d83330eca (affected)
Linux	Linux	Default status: affected 2.6.36 (affected) 0 up to but excluding 2.6.36 (unaffected) 5.4.295 up to and including 5.4.* (unaffected) 5.10.239 up to and including 5.10.* (unaffected) 5.15.186 up to and including 5.15.* (unaffected) 6.1.142 up to and including 6.1.* (unaffected) 6.6.94 up to and including 6.6.* (unaffected) 6.12.34 up to and including 6.12.* (unaffected) 6.15.3 up to and including 6.15.* (unaffected) 6.16 up to and including * (unaffected)