CVE-2026-74732

A flaw was found in the Linux kernel's AMD display (drm/amd/display) driver. When a user turns off the display over HDMI on systems with older DCE timing generators, the driver attempts to call a function (is_tg_enabled) that may not be implemented. This unconditional call can lead to a NULL pointer dereference, resulting in a system crash and a Denial of Service (DoS).

A moderate-impact flaw was found in the Linux kernel's AMD display driver (drm/amd/display) as shipped in Red Hat Enterprise Linux and Red Hat In-Vehicle OS. Some older DCE timing generators do not implement the is_tg_enabled operation in their ops table. When a display is turned off over HDMI on systems with such hardware (for example Southern Islands AMD dGPUs), the dce110_set_avmute() code path calls this operation unconditionally, which causes a NULL pointer dereference and a kernel crash, resulting in a local denial of service. Confidentiality and integrity are not affected. The issue is not network-reachable: triggering it requires local access to a system with an affected AMD graphics configuration and turning the display off over HDMI. The fix is currently deferred for the affected Red Hat Enterprise Linux and Red Hat In-Vehicle OS streams; the residual risk is limited to a local denial of service (kernel panic) on the affected AMD hardware. The flaw is rated Moderate, with a Red Hat CVSS 3.1 score of 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

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.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.