CVE-2024-42227

What it actually does

The vulnerability stems from using memcpy to copy between overlapping addresses (&mode_lib->mp.Watermark and &locals->Watermark) inside dml_core_mode_programming, producing undefined behavior and potential memory corruption in the AMD display mode programming path.

Why it matters to the business

Systems using affected Linux kernels with AMD GPUs may experience graphics instability or crashes during display configuration changes, increasing operational risk for graphics workloads until kernels are updated.

How an attack unfolds

An attacker with local access crafts or triggers display mode programming operations that cause the overlapping Watermark structures to be processed, invoking the unsafe memcpy and resulting in corrupted memory that can crash the system.

How to fix it

Upgrade the Linux kernel to a version containing commit 9342da15f2491d8600eca89c8e0da08876fb969b or later; rebuild and reboot with the patched kernel.

How to confirm the fix worked

Verify the presence of memmove instead of memcpy for the Watermark copy in dml_core_mode_programming after applying the update; confirm the running kernel reports the fixed commit hash.

Typical attack path

1. Obtain local user access on a Linux system with AMD display hardware
2. Trigger AMD display mode programming paths that reach dml_core_mode_programming
3. Force conditions where the two Watermark structures occupy the same address
4. Invoke memcpy on the overlapping region to induce memory corruption or crash

How to detect it

Review system logs for kernel oops or display driver crashes coinciding with display mode changes; inspect AMD display code paths for unexpected memory corruption symptoms after mode programming events.

What your security team should do

• Apply the kernel update containing commit 9342da15f2491d8600eca89c8e0da08876fb969b as soon as vendor packages are available
• Prioritize systems with AMD GPUs in graphics or desktop workloads
• Test patched kernels in staging environments before broad deployment
• Monitor vendor kernel advisories for backported fixes in supported distributions