CVE-2023-53815
posix-timers: Prevent RT livelock in itimer_delete()
Description
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.
INFO
Published Date :
Dec. 9, 2025, 1:16 a.m.
Last Modified :
Dec. 9, 2025, 6:37 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Replace spin_unlock() with timer_wait_running().
- Ensure timer callback completes.
- Handle concurrent timer expirations properly.
- Apply the kernel patch for posix-timers.
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2023-53815.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-53815 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-53815
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2023-53815 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 09, 2025
Action Type Old Value New Value Added Description 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. Added Reference https://git.kernel.org/stable/c/0670c4c567b27bd8f999a943028f4fe60d1a1106 Added Reference https://git.kernel.org/stable/c/9d9e522010eb5685d8b53e8a24320653d9d4cbbf Added Reference https://git.kernel.org/stable/c/c1968bb8a28625cc95d2ad3ca872ab98c9c36d59 Added Reference https://git.kernel.org/stable/c/e7aff15ba29ba4b3052786b1636fa5c4aa39e179 Added Reference https://git.kernel.org/stable/c/f1be1ed32daa053484222f7f9beb2b16c624dffd Added Reference https://git.kernel.org/stable/c/f9bd298e3e4d3fd6e19f017789a42d0f332cd555