CVE-2026-93269

A flaw was found in the Linux kernel's ext4 file system. A local user can cause a Denial of Service (DoS) by triggering a deadlock during file extent migration operations. Under specific timing conditions, conflicting lock dependencies between extent migration and background inode cleanup leave kernel processes permanently blocked, resulting in a system freeze.

A low-impact denial of service vulnerability was found in the Linux kernel's ext4 file system. A local user able to run file extent migration operations on an ext4 filesystem can trigger a circular lock dependency between the s_writepages_rwsem writepages lock, held during extent migration (EXT4_IOC_MIGRATE), and the sb_internal freeze protection held during background inode cleanup. Under specific timing conditions the two paths wait on each other, leaving kernel processes permanently blocked and resulting in a system freeze. Exploitation requires winning a race between migration and inode eviction and affects only system availability; no confidentiality or integrity impact is indicated. Red Hat Enterprise Linux 8, 9, and 10, Red Hat In-Vehicle OS, and OpenShift Container Platform (via its RHEL CoreOS kernels) are affected. The fix is currently deferred for these streams, so the residual risk of a local user hanging the system remains until a patched kernel is released. Red Hat Enterprise Linux 7 is not affected because the vulnerable code is not present in that stream. Red Hat assessed the impact of this flaw as low rather than the moderate severity suggested by the maximum CVSS 3.1 score (AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H), reflecting the local attack vector, the timing-dependent race required to trigger the deadlock, and the availability-only impact.

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 for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.