CVE-2022-50095 Information

Jun 19, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

posix-cpu-timers: Cleanup CPU timers before freeing them during exec

Commit 55e8c8eb2c7b (\posix-cpu-timers: Store a reference to a pid not a task) started looking up tasks by PID when deleting a CPU timer.

When a non-leader thread calls execve it will switch PIDs with the leader process. Then as it calls exit_itimers posix_cpu_timer_del cannot find the task because the timer still points out to the old PID.

That means that armed timers won’t be disarmed that is they won’t be removed from the timerqueue_list. exit_itimers will still release their memory and when that list is later processed it leads to a use-after-free.

Clean up the timers from the de-threaded task before freeing them. This prevents a reported use-after-free.

Reference

https://git.kernel.org/stable/c/541840859ace9c2ccebc32fa9e376c7bd3def490 https://git.kernel.org/stable/c/9e255ed238fc67058df87b0388ad6d4b2ef3a2bd https://git.kernel.org/stable/c/b2fc1723eb65abb83e00d5f011de670296af0b28 https://git.kernel.org/stable/c/e362359ace6f87c201531872486ff295df306d13 https://git.kernel.org/stable/c/e8cb6e8fd9890780f1bfcf5592889e1b879e779c

CNNVD-202506-2383 (Published: 2025-06-18)

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