CVE-2024-43903

What it actually does

Null pointer dereference in amdgpu_dm_plane_handle_cursor_update when 'afb' is null after an earlier assumption it could be null, leading to memory corruption in the AMD display driver.

Why it matters to the business

Systems using affected Linux kernels on AMD GPUs may experience crashes or instability during graphics operations, increasing downtime risk for dependent workloads; prevalence in Debian and Android ecosystems amplifies exposure for many deployments.

How an attack unfolds

An attacker with local access triggers cursor update paths in the AMD display driver such that 'afb' remains null, causing the kernel to dereference it and resulting in a crash or potential memory corruption.

How to fix it

Upgrade to fixed kernel versions such as Debian 6.1.106-1 or later equivalents; apply vendor patches for the AMD display driver null check.

How to confirm the fix worked

Verify kernel version is at or above the fixed release, review source for the added null check on 'afb' in amdgpu_dm_plane_handle_cursor_update, and test cursor operations on AMD hardware.

Typical attack path

1. Gain local access to a system with vulnerable AMD GPU and kernel
2. Craft graphics or cursor update operations to reach amdgpu_dm_plane_handle_cursor_update with 'afb' unset
3. Trigger null dereference to induce kernel panic or corruption

How to detect it

Review kernel logs for null pointer dereference errors in amdgpu_dm_plane.c or related display driver crashes; correlate with cursor update activity if possible.

What your security team should do

• Apply kernel updates to 6.1.106-1 or newer immediately on affected systems
• Monitor for kernel oops or panic logs related to amdgpu_dm
• Prioritize AMD GPU hosts in patching queues given memory corruption family