CVE-2024-46776

What it actually does

Potential null pointer dereference in AMD display driver code path where DC_LOG_DC is invoked before validating link->link_enc, classified as REVERSE_INULL.

Why it matters to the business

System instability or crashes on Linux systems with AMD GPUs during display operations, increasing downtime risk for affected servers and workstations.

How an attack unfolds

An attacker with local access triggers the vulnerable display code path through crafted display configuration or mode-setting operations that cause link_enc to be null when the log macro executes, leading to invalid memory access.

How to fix it

Update the Linux kernel to a version containing commit 874e3bb302f97b94ac548959ec4f925b8e7b45e2 or later stable releases that reorder the null check before the log statement.

How to confirm the fix worked

Verify the presence of the fix by inspecting the drm/amd/display source for the reordered check and log, or confirm kernel build includes the referenced commit hash.

Typical attack path

1. Obtain local access on a Linux system with AMD display hardware
2. Trigger display driver code involving link state changes or logging
3. Force link->link_enc to be null prior to the DC_LOG_DC call
4. Cause kernel memory fault or corruption

How to detect it

Review kernel logs for NULL pointer dereference oops in amd_display or drm modules around the time of display configuration changes.

What your security team should do

• Apply the kernel patch containing the referenced commit as soon as possible
• Monitor for kernel oops or panic logs related to amd_display
• Restrict unprivileged local access until systems are updated