Improper locking in Linux kernel - CVE-2021-47256
Published: June 13, 2024 / Updated: May 13, 2025
Vulnerability identifier: #VU92016
CSH Severity: Low
CVSS v4: 6.8 [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]
CVE-ID: CVE-2021-47256
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to improper locking within the memory_failure() function in mm/memory-failure.c. A local user can perform a denial of service (DoS) attack.
Affected software
Linux kernel
How to mitigate CVE-2021-47256
Install update from vendor's website.
Linux kernel - addressed in versions 4.14.238, 4.19.196, 5.4.128, 5.10.46, 5.12.13, 5.13
External References
- https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c
- https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872
- https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527
- https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306
- https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56
- https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a
- https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.238
- https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.196
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.46
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.128