SB20251226295 - Integer underflow in Linux kernel ext4
Published: December 26, 2025 Updated: December 31, 2025
Security Bulletin ID
SB20251226295
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Integer underflow (CVE-ID: CVE-2023-54021)
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to integer underflow within the ext4_mb_normalize_request() function in fs/ext4/mballoc.c. A local user can execute arbitrary code.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/2479bb6cbdb4d56b807bbe5229e3e26a6f1f4530
- https://git.kernel.org/stable/c/390eee955d4de4662db5e3e9e9a9eae020432cb7
- https://git.kernel.org/stable/c/3ca3005b502ca8ea87d6a344323b179b48c4e4a3
- https://git.kernel.org/stable/c/abb330ffaa3a0ae7ce632e28c9260b461c01f19f
- https://git.kernel.org/stable/c/b07ffe6927c75d99af534d685282ea188d9f71a6
- https://git.kernel.org/stable/c/bc4a3e1d07a86ae5845321d371190244acacb2f2
- https://git.kernel.org/stable/c/c6bee8970075b256fc1b07bf4873049219380818
- https://git.kernel.org/stable/c/cee78217a7ae72d11c2e21e1a5263b8044489823
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.244