Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.10, < 6.12.21 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/6afe2ea2daec156bd94ad2c5a6f4f4c48240dcd3Patch
- https://git.kernel.org/stable/c/75845c6c1a64483e9985302793dbf0dfa5f71e32Patch
- https://git.kernel.org/stable/c/f6a3cf833188e897c97028cd7b926e3f2cb1a8c0Patch
FAQ
What is CVE-2025-21893?
CVE-2025-21893 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 ...
How severe is CVE-2025-21893?
CVE-2025-21893 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-21893?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.