CVE-2023-53815

In the Linux kernel, the following vulnerability has been resolved: posix-timers: Prevent RT livelock in itimer_delete() itimer_delete() has a retry loop when the timer is concurrently expired. On non-RT kernels this just spin-waits until the timer callback has completed, except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK enabled. In that case and on RT kernels the existing task could live lock when preempting the task which does the timer delivery. Replace spin_unlock() with an invocation of timer_wait_running() to handle it the same way as the other retry loops in the posix timer code.

Package Linux Kernel
Published 2025-12-09
Last modified 2026-04-15
Patch available
Yes

Affected versions

Linux kernel versions 5.4 and later are affected. Fixed in 5.10.188, 5.15.121, 6.1.39, 6.3.13, 6.4.4, 6.5 and their respective stable series.

Affected from
≥ 5.4
Fixed in
✓ 5.10.188 5.10.x ✓ 5.15.121 5.15.x ✓ 6.1.39 6.1.x ✓ 6.3.13 6.3.x ✓ 6.4.4 6.4.x ✓ 6.5

References

The following references provide additional information about CVE-2023-53815 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2023-53815?

    CVE-2023-53815 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.4 onward and has been patched in 5.10.188, 5.15.121, 6.1.39 and others. CVE-2023-53815 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2023-53815?

    Yes — CVE-2023-53815 has been patched. Fixed versions include 5.10.188, 5.15.121, 6.1.39 and others. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2023-53815 actively exploited?

    No — CVE-2023-53815 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.