In the Linux kernel, DRM code for AMD GPUs incorrectly assumes the presence of is_tg_enabled in some DCE timing generator ops tables. When a display is turned off over HDMI, the code waits for AV mute frames and unconditionally calls is_tg_enabled, dereferencing a NULL pointer on older Southern Islands GPUs. This results in a kernel crash, causing a denial of service.

The vulnerability affects the Linux kernel AMD DRM driver on systems that run older DCE timing generators without is_tg_enabled support, notably AMD Southern Islands GPUs. It applies to any Linux installation where the kernel has not yet been patched to include the commit that checks for the ops table.

While the exploit requires the ability to manipulate the HDMI display or trigger a display off event, the resulting crash is local to the affected system and not directly exploitable for code execution. The CVSS score is 5.5, the EPSS score is < 1%, and the KEV status indicates it is not listed, implying no widely documented exploitation. Nonetheless, patching is recommended due to the availability of the fix in newer kernels.