CVEs / CVE-2025-38352
CVE-2025-38352: Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability
- Known exploited in the CISA KEV catalog since 4 Sep 2025
- high 7.8 CVSS 3.1 (from the CNA)
- EPSS 1.35% chance of exploitation in the next 30 days, higher than 71% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Linux kernel contains a time-of-check time-of-use (TOCTOU) race condition vulnerability that has a high impact on confidentiality, integrity, and availability.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before 78a4b8e3795b31dae58762bc091bb0f4f74a2200 | 78a4b8e3795b31dae58762bc091bb0f4f74a2200 |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before c076635b3a42771ace7d276de8dc3bc76ee2ba1b | c076635b3a42771ace7d276de8dc3bc76ee2ba1b |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before 2f3daa04a9328220de46f0d5c919a6c0073a9f0b | 2f3daa04a9328220de46f0d5c919a6c0073a9f0b |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before 764a7a5dfda23f69919441f2eac2a83e7db6e5bb | 764a7a5dfda23f69919441f2eac2a83e7db6e5bb |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff | 2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before c29d5318708e67ac13c1b6fc1007d179fb65b4d7 | c29d5318708e67ac13c1b6fc1007d179fb65b4d7 |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before 460188bc042a3f40f72d34b9f7fc6ee66b0b757b | 460188bc042a3f40f72d34b9f7fc6ee66b0b757b |
| Linux Linux | from 0bdd2ed4138ec04e09b4f8165981efc99e439f55, before f90fff1e152dedf52b932240ebbd670d83330eca | f90fff1e152dedf52b932240ebbd670d83330eca |
| Linux Linux | 2.6.36 | — |
| Product | Affected | Fixed in |
|---|---|---|
| Kernel (Linux) | from 2.6.36, before 5.4.295 | 5.4.295 |
| Kernel (Linux) | from 5.5.0, before 5.10.239 | 5.10.239 |
| Kernel (Linux) | from 5.11.0, before 5.15.186 | 5.15.186 |
| Kernel (Linux) | from 5.16.0, before 6.1.142 | 6.1.142 |
| Kernel (Linux) | from 6.2.0, before 6.6.94 | 6.6.94 |
| Kernel (Linux) | from 6.7.0, before 6.12.34 | 6.12.34 |
| Kernel (Linux) | from 6.13.0, before 6.15.3 | 6.15.3 |
Exploitation
| In CISA KEV since | 4 Sep 2025 |
|---|---|
| Due date for US federal agencies | 25 Sep 2025 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 7.8 highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HScored by the CNA (416baaa9-dc9f-4396-8d5f-8c081fb06d67) |
|---|---|
| Weakness | CWE-367 |
References
- CVE-2025-38352 on NVD
- CVE-2025-38352 in the CISA KEV catalog
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff (cited by CISA)
- https://source.android.com/docs/security/bulletin/2025-09-01 (cited by CISA)
- CVE-2025-38352 on OSV
- https://git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff Patch
- https://git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b Patch
- https://git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b Patch
- https://git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb Patch
- https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200 Patch
- https://git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b Patch
- https://git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7 Patch
- https://git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca Patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Mailing List, Third Party Advisory
- https://github.com/farazsth98/chronomaly Exploit
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-38352 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.