CVE-2026-43305

A flaw was found in the drm/amd/display component of the Linux kernel. A mismatched unlock operation for the DMUB hardware (HW) lock in the HWSS fast path can occur. This happens because the logic for determining when to use the lock differs from the logic for when to unlock it. When the fast path is utilized on systems without FAMS (Fast Access Memory Support) hardware, this discrepancy can lead to a system hang, resulting in a Denial of Service (DoS).

This flaw is rated with a Low impact because exploitation is constrained to local users on systems configured with specific AMD graphics hardware and results only in a denial of service. Typical Red Hat Enterprise Linux server deployments operate headless or without affected AMD display adapters, significantly limiting real-world exposure. The failure arises from an inconsistent locking path during display operations on hardware lacking Fast Access Memory Support, which can hang the system without compromising confidentiality or integrity.

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.