SecuriTricks - CVE-2025-21893

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.

Product(s) Impacted

Vendor	Product	Versions
Linux	Linux Kernel	*

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-416

Use After Free

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	linux	linux_kernel	/	/	/	/	/	/	/	/

References

https://git.kernel.org/stable/c/6afe2ea2daec156bd94ad2c5a6f4f4c48240dcd3

https://git.kernel.org/stable/c/75845c6c1a64483e9985302793dbf0dfa5f71e32

https://git.kernel.org/stable/c/f6a3cf833188e897c97028cd7b926e3f2cb1a8c0

CVSS Score

7.8 / 10

CVSS Data - 3.1

Attack Vector: LOCAL
Attack Complexity: LOW
Privileges Required: LOW
Scope: UNCHANGED
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

View Vector String

Timeline

Published: March 31, 2025, 8:15 p.m.
Last Modified: April 1, 2025, 8:26 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVE-2025-21893