kernel: futex: Avoid private hash use-after-free on final put (CVE-2026-80758)

Overview

A flaw was found in the Linux kernel's futex subsystem. A race condition in the futex_private_hash_put() function allows a local attacker to trigger a use-after-free vulnerability. This occurs when a reference to a private hash is dropped prematurely, enabling another process to free the memory while the original task still holds a pointer to it. Successful exploitation could lead to a denial of service or potentially privilege escalation.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-26 · vex

kernel: futex: Avoid private hash use-after-free on final put — rated Moderate by Red Hat. Released 2026-09-04, updated 2026-10-26.

Affected:

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 9
• Red Hat OpenShift Container Platform 4

No fix planned:

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 9
• Red Hat OpenShift Container Platform 4

Not affected:

• Red Hat Enterprise Linux 6
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8
• Red Hat OpenShift Container Platform 4

Remediation

Fix deferred

Workarounds / mitigations:

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