CVE-2025-21893 (GCVE-0-2025-21893)

Vulnerability from cvelistv5 – Published: 2025-03-31 19:41 – Updated: 2026-05-11 21:08
VLAI?
Title
keys: Fix UAF in key_put()
Summary
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.
Severity ?
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 9578e327b2b4935a25d49e3891b8fcca9b6c10c6 , < 6afe2ea2daec156bd94ad2c5a6f4f4c48240dcd3 (git)
Affected: 9578e327b2b4935a25d49e3891b8fcca9b6c10c6 , < f6a3cf833188e897c97028cd7b926e3f2cb1a8c0 (git)
Affected: 9578e327b2b4935a25d49e3891b8fcca9b6c10c6 , < 75845c6c1a64483e9985302793dbf0dfa5f71e32 (git)
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Linux Linux Affected: 6.10
Unaffected: 0 , < 6.10 (semver)
Unaffected: 6.12.21 , ≤ 6.12.* (semver)
Unaffected: 6.13.9 , ≤ 6.13.* (semver)
Unaffected: 6.14 , ≤ * (original_commit_for_fix)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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