#VU88214 Improper locking in Linux kernel - CVE-2021-46921
Published: April 8, 2024 / Updated: May 14, 2025
Vulnerability identifier: #VU88214
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-46921
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a local user to perform a denial of service attack.
The vulnerability exists due to improper locking within the queued_write_lock_slowpath() function in kernel/locking/qrwlock.c. A local user can crash the kernel.
Remediation
Install updates from vendor's website.
External links
- https://git.kernel.org/stable/c/5902f9453a313be8fe78cbd7e7ca9dba9319fc6e
- https://git.kernel.org/stable/c/82808cc026811fbc3ecf0c0b267a12a339eead56
- https://git.kernel.org/stable/c/82fa9ced35d88581cffa4a1c856fc41fca96d80a
- https://git.kernel.org/stable/c/d558fcdb17139728347bccc60a16af3e639649d2
- https://git.kernel.org/stable/c/84a24bf8c52e66b7ac89ada5e3cfbe72d65c1896
- https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.189
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.33
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.17
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.115