CVE-2023-53780

Vulnerability

The vulnerability is in the AMD display driver (drm/amd/display) of the Linux kernel. When UCLK p-state is not supported, the driver incorrectly sets the FCLK p-state change watermark based on a dummy p-state latency instead of the actual FCLK p-state change latency. This miscalculation can lead to an underflow condition.

Exploitation

The issue is triggered during display mode transitions that require FCLK p-state changes. An attacker with local access could potentially exploit this by inducing specific display configurations or workloads that cause the underflow, though the primary impact is system instability rather than direct code execution.

Impact

The underflow can cause display corruption, system hangs, or denial of service. Since it affects the display subsystem, it may lead to visual artifacts or complete loss of display output, impacting system usability.

Mitigation

The fix was committed to the Linux kernel stable tree [1]. Users should apply the latest kernel updates from their distribution to address this issue. No workaround is available other than patching.