Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability (CVE-2025-38352)

A local attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2025-09-25 under CISA BOD 22-01.

This is a Software Vulnerability (CWE-367) (CWE-367) vulnerability in Linux Kernel. 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. Exploitation requires local access, higher attack complexity, no authentication required, and no user interaction required.

Probably yes if any of these apply:

Active exploitation documented in the wild. Threat-research write-up: https://github.com/farazsth98/chronomaly