CVE-2026-23224
kernel: Linux kernel erofs: Denial of Service via Use-After-Free in file-backed directio mounts
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · February 18, 2026
Updated · August 5, 2026
Description
A flaw was found in the Linux kernel's erofs filesystem. A local user could exploit a Use-After-Free (UAF) vulnerability, which occurs due to a race condition when performing file-backed mounts with the 'directio' option. This flaw can lead to a kernel panic, resulting in a Denial of Service (DoS) for the system.
Statement
A use after free can occur in EROFS file backed mounts when the directio option is enabled. The read path allocates an erofs_fileio_rq that contains a bio and an embedded kiocb. The request is submitted through vfs_iocb_iter_read into the backing filesystem direct IO path. When direct IO completes asynchronously the completion callback erofs_fileio_ki_complete can run in the dio completion workqueue and free the request structure while the submit side still has execution paths that may access fields derived from the kiocb such as ki_filp. This race can result in a kernel NULL dereference or a use after free and can panic the kernel. For the CVSS the PR is L in a paranoid configuration because the affected configuration might be reachable in some environments through delegated mount capabilities or misconfiguration.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 6.6CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
CWE not specified