kernel: net/smc: unregister the connection before draining the rx tasklet (CVE-2026-80979)

Overview

A flaw was found in the Linux kernel's Shared Memory Communications (SMC) component. During connection termination, the SMC component may fail to properly unregister a connection before draining its receive tasklet. This can lead to a use-after-free vulnerability, where a freed memory buffer is subsequently dereferenced. A local attacker could potentially exploit this to cause a system crash, resulting in a denial of service, or potentially achieve arbitrary code execution.

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 2026-10-24 · vex

kernel: net/smc: unregister the connection before draining the rx tasklet — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-10-24.

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.