CVE-2025-21893
- Source
- https://cve.org/CVERecord?id=CVE-2025-21893
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21893.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2025-21893
- Downstream
- Related
- Published
- 2025-03-31T19:41:46Z
- Modified
- 2026-08-12T03:51:31Z
- Severity
-
- 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- keys: Fix UAF in key_put()
- Details
-
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.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21893.json" }- References
-
- https://git.kernel.org/stable/c/6afe2ea2daec156bd94ad2c5a6f4f4c48240dcd3
- https://git.kernel.org/stable/c/75845c6c1a64483e9985302793dbf0dfa5f71e32
- https://git.kernel.org/stable/c/f6a3cf833188e897c97028cd7b926e3f2cb1a8c0
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21893.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-21893
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git