kernel: usb: typec: thunderbolt: Disable work before freeing tbt on remove (CVE-2026-89737)

Overview

A flaw was found in the Linux kernel's USB Type-C Thunderbolt driver. The tbt_altmode_remove() function fails to properly disable and drain work items before freeing associated plug and cable references. This oversight can lead to a use-after-free vulnerability, where the system attempts to access memory that has already been released. A local attacker could potentially exploit this to cause a system crash, leading to a denial of service, or possibly 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 2026-10-21 · vex

kernel: usb: typec: thunderbolt: Disable work before freeing tbt on remove — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-10-21.

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.