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.
History

Mon, 16 Jun 2025 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/o:redhat:enterprise_linux:10.0
Vendors & Products Redhat
Redhat enterprise Linux

Fri, 11 Apr 2025 03:00:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Low

threat_severity

Moderate


Tue, 08 Apr 2025 16:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Wed, 02 Apr 2025 02:15:00 +0000


Mon, 31 Mar 2025 21:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 31 Mar 2025 20:00:00 +0000

Type Values Removed Values Added
Description 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.
Title keys: Fix UAF in key_put()
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-03-31T19:41:46.137Z

Updated: 2025-05-04T07:23:40.081Z

Reserved: 2024-12-29T08:45:45.783Z

Link: CVE-2025-21893

cve-icon Vulnrichment

Updated: 2025-03-31T20:45:41.300Z

cve-icon NVD

Status : Analyzed

Published: 2025-03-31T20:15:14.613

Modified: 2025-04-08T15:48:59.010

Link: CVE-2025-21893

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-03-31T00:00:00Z

Links: CVE-2025-21893 - Bugzilla