In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check for tg ops in dce110_set_avmute Some older DCE timing… (CVE-2026-74732)

The vulnerability involves the drm/amd/display component of the Linux kernel where the dce110_set_avmute function calls is_tg_enabled unconditionally on timing generators. Some older DCE timing generators do not implement this operation, leading to a NULL pointer dereference on Southern Islands discrete GPUs during HDMI display shutdown. The fix involved adding checks to ensure the timing generator and required operations exist before waiting for AV mute frames, preventing the NULL pointer dereference.

This vulnerability can cause a NULL pointer dereference leading to a kernel crash or denial of service when turning off the display over HDMI on affected hardware (Southern Islands dGPUs). There is no indication of code execution or privilege escalation from the provided data.

A fix has been applied in the Linux kernel source code to check for the presence of timing generator operations before calling them. Users should update their Linux kernel to a version that includes this fix. Patch status is not explicitly stated; check the vendor or Linux kernel advisory for the exact fixed versions and update accordingly.