CVE-2025-21893 Affecting linux-virt package, versions <6.12.22-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.01% (2nd percentile)

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  • Snyk IDSNYK-MINIMOSLATEST-LINUXVIRT-13307497
  • published6 Oct 2025
  • disclosed31 Mar 2025

Introduced: 31 Mar 2025

CVE-2025-21893  (opens in a new tab)

How to fix?

Upgrade Minimos:latest linux-virt to version 6.12.22-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-virt package and not the linux-virt package as distributed by Minimos. See How to fix? for Minimos:latest relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

keys: Fix UAF in key_put()

Once a key's reference count has been reduced to 0, the garbage collector thread may destroy it at any time and so key_put() is not allowed to touch the key after that point. The most key_put() is normally allowed to do is to touch key_gc_work as that's a static global variable.

However, in an effort to speed up the reclamation of quota, this is now done in key_put() once the key's usage is reduced to 0 - but now the code is looking at the key after the deadline, which is forbidden.

Fix this by using a flag to indicate that a key can be gc'd now rather than looking at the key's refcount in the garbage collector.

CVSS Base Scores

version 3.1