CVE-2026-89609

A flaw was found in the eCryptfs component of the Linux kernel. A race condition occurs during the cleanup of the daemon message queue because a required lock is not held. This can lead to unpredictable system behavior or instability due to concurrent access to shared message context lists.

A MODERATE severity race condition flaw was found in the eCryptfs component of the Linux kernel. When an eCryptfs daemon terminates, ecryptfs_exorcise_daemon() drops the daemon's queued messages and moves those message contexts back to the free list without holding the ecryptfs_msg_ctx_lists_mux lock, which ecryptfs_msg_ctx_alloc_to_free() requires. A local low-privileged attacker able to trigger concurrent use of the global message context lists could race with this cleanup path, resulting in corruption of the shared list state and unpredictable system behavior or instability. Red Hat rated this flaw MODERATE (CVSS 7.0, CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) based on the local attack vector, the low privileges required, and the high attack complexity needed to reliably win the race; this differs from the upstream CVE.org score of 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), which assesses a lower attack complexity. The Red Hat Enterprise Linux kernel and kernel-rt streams evaluated for this flaw, as well as the OpenShift Container Platform 4 RHCOS components, are not affected because the vulnerable code is not present in those builds. OpenShift Container Platform 5.0 and 5.1 are affected, and the fix is currently deferred for those streams; the residual risk is that a local user on an affected node could trigger the race condition and cause system instability, although the local access requirement and high attack complexity limit practical exploitability.

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.