Technical impact
The vulnerability arises from inconsistent handling of the DMUB hardware lock in the AMD DRM display driver. When the kernel logic for acquiring the lock does not align with the logic for releasing it, the system can block indefinitely during the fast-path operation on AMD ASICs that lack FAMS support. This results in a denial-of-service condition that halts driver activity and can propagate to a complete kernel hang, severely impacting system availability. The flaw is rooted in timing and lock protocol misuse, and in improper synchronization leading to deadlock (CWE-832, CWE-667).
Affected Systems
All Linux systems that run a kernel containing the AMD DRM display driver with DMUB lock support and employ the HWSS fast path are potentially affected. The CVE indicates the Linux kernel as the only vendor, with no version constraints, which implies any kernel build that still contains the pre-fix lock logic is vulnerable.
Risk and Exploitability
The CVE lists a CVSS score of 5.5 and an EPSS score of < 1%, indicating a moderate severity and very low likelihood of exploitation. The vulnerability is not listed in CISA's KEV catalog. Based on the description, it is inferred that an attacker would need local or privileged access to manipulate GPU request paths, so the attack vector is local. The defect can be triggered by manipulating GPU request paths that engage the fast path, and an attacker with local access could potentially cause a system halt. The requirement for driver interaction suggests that exploitation would be environment-specific and likely require elevated permissions or close proximity to the compromised machine.
