PT-2025-4315 · Linux+4 · Linux Kernel+4
Ji Fa
·
Published
2025-01-08
·
Updated
2026-05-26
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CVE-2025-21634
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
A warning was found in the Linux kernel related to the cgroup/cpuset functionality. The issue is caused by the
kernfs break active protection function when writing to cpuset.cpus and the cgroup is removed concurrently. This warning can lead to a deadlock due to a circular locking dependency involving cgroup mutex. The commit 3a5a6d0c2b03 made cpuset hotplug workfn asynchronous, which involves calling flush work() and can create a multiple processes circular locking dependency. To avoid deadlock, the commit 76bb5ab8f6e3 added kernfs break active protection in cpuset write resmask. However, after the commit 2125c0034c5d, cpuset write resmask no longer needs to wait for the hotplug to finish, making concurrent hotplug and cpuset operations no longer possible and thus removing the deadlock.Recommendations
To fix this warning, remove the
kernfs break active protection operation in cpuset write resmask.Exploit
Fix
Improper Locking
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Debian
Linuxmint
Linux Kernel
Ubuntu