CVE-2025-38352

Published Jul 22, 2025

Last updated 22 days ago

Linux Kernel

Overview

AI description

Automated description summarized from trusted sources.

CVE-2025-38352 is a vulnerability that exists in the Linux kernel, specifically within the handling of POSIX CPU timers. The vulnerability stems from a race condition between `handle_posix_cpu_timers()` and `posix_cpu_timer_del()`. This race condition can occur when a non-autoreaping task that is exiting has already passed `exit_notify()` and calls `handle_posix_cpu_timers()` from an interrupt request (IRQ). If a concurrent `posix_cpu_timer_del()` runs at the same time, it might not detect that `timer->it.cpu.firing != 0`, which can cause `cpu_timer_task_rcu()` and/or `lock_task_sighand()` to fail. This vulnerability can be exploited to gain elevated privileges on Android devices.

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: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status: Analyzed
Products: linux_kernel, debian_linux

Risk scores

CVSS 3.1

Type: Secondary
Base score: 7.4
Impact score: 5.9
Exploitability score: 1.4
Vector string: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: HIGH

Known exploits

Data from CISA

Vulnerability name: Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability
Exploit added on: Sep 4, 2025
Exploit action due: Sep 25, 2025
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.

Weaknesses

134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-367

Hype score: Not currently trending

Configurations

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References

Sources include official advisories and independent security research.