SB20260424281 - Use-after-free in Linux kernel ext4
Published: April 24, 2026
Security Bulletin ID
SB20260424281
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-31446)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in ext4 update_super_work when racing with filesystem unmount. A local user can trigger error notification activity during unmount to cause a denial of service.
The issue occurs because sysfs notification may access a freed kernfs_node after sysfs teardown during the race.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/034053378dd81837fd6c7a43b37ee2e58d4f0b4e
- https://git.kernel.org/stable/c/08b10e6f37fc533a759e9833af0692242e8b3f93
- https://git.kernel.org/stable/c/9449f99ba04f5dd1c8423ad8a90b3651d7240d1d
- https://git.kernel.org/stable/c/c4d829737329f2290dd41e290b7d75effdb2a7ff
- https://git.kernel.org/stable/c/c8fe17a1b308c3d8c703ebfb049b325f844342c3
- https://git.kernel.org/stable/c/c97e282f7bfd0c3554c63d289964a5ca6a1d2ffe
- https://git.kernel.org/stable/c/d15e4b0a418537aafa56b2cb80d44add83e83697