CVE-2025-38352
posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()
- Published
- Updated
- Reserved
- Assigned by
- Linux
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability.
- Added
- 4 Sept 2025
- Fix due (US federal)
- 25 Sept 2025
- Used by ransomware
- Not known
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.4% · top 28% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < 78a4b8e3795b31dae58762bc091bb0f4f74a2200
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < c076635b3a42771ace7d276de8dc3bc76ee2ba1b
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < 2f3daa04a9328220de46f0d5c919a6c0073a9f0b
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < 764a7a5dfda23f69919441f2eac2a83e7db6e5bb
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < c29d5318708e67ac13c1b6fc1007d179fb65b4d7
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < 460188bc042a3f40f72d34b9f7fc6ee66b0b757b
- affected 0bdd2ed4138ec04e09b4f8165981efc99e439f55 – < f90fff1e152dedf52b932240ebbd670d83330eca
- affected 2.6.36
- unaffected < 2.6.36
- unaffected 5.4.295 – ≤ 5.4.*
- unaffected 5.10.239 – ≤ 5.10.*
- unaffected 5.15.186 – ≤ 5.15.*
- unaffected 6.1.142 – ≤ 6.1.*
- unaffected 6.6.94 – ≤ 6.6.*
- unaffected 6.12.34 – ≤ 6.12.*
- unaffected 6.15.3 – ≤ 6.15.*
- unaffected 6.16 – ≤ *
References (12)
- https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200 (opens in a new tab)
- https://git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b (opens in a new tab)
- https://git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b (opens in a new tab)
- https://git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb (opens in a new tab)
- https://git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff (opens in a new tab)
- https://git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7 (opens in a new tab)
- https://git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b (opens in a new tab)
- https://git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca (opens in a new tab)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-38352 (opens in a new tab)government-resource
- https://github.com/farazsth98/chronomaly (opens in a new tab)exploit
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-38352)Record last updated .