CVE-2024-42119

What it actually does

The vulnerability stems from using ENGINE_ID_UNKNOWN (-1) as an array index when locating free audio resources in the AMD display driver, allowing potential out-of-bounds access or overrun when the engine identifier is uninitialized.

Why it matters to the business

Unpatched Linux kernel systems with AMD GPUs may experience display instability, crashes, or denial of service during graphics initialization, impacting workstation and server reliability for organizations relying on the affected kernel versions.

How an attack unfolds

An attacker triggers the audio allocation path in the display driver with an uninitialized engine_id value, causing the kernel to index into an array with -1 and potentially corrupt adjacent memory structures.

How to fix it

Update the Linux kernel to a version containing commit 9eb4db08a808e3a3ba59193aeb84a57a6dc4d8c9 or later; rebuild and deploy the patched kernel across affected systems.

How to confirm the fix worked

Confirm the running kernel contains commit 9eb4db08a808e3a3ba59193aeb84a57a6dc4d8c9 via git log or kernel version string; recompile with the fix and verify the audio lookup function now returns NULL for unknown engine IDs.

Typical attack path

1. Identify a system running an unpatched Linux kernel with AMD display hardware
2. Trigger display or audio initialization code paths that leave engine_id uninitialized
3. Force the driver to call the free-audio lookup function with ENGINE_ID_UNKNOWN
4. Exploit the resulting overrun for memory corruption or denial of service

How to detect it

Search kernel logs and crash dumps for display driver faults referencing audio allocation or engine_id values near -1; examine call stacks involving drm/amd/display audio functions on systems that have not yet applied the fix.

What your security team should do

• Prioritize kernel updates on all AMD GPU systems within the next maintenance window
• Monitor upstream stable kernel releases for backports of the referenced commit
• Test the patched kernel in staging environments before broad deployment
• Review display driver initialization logs for signs of engine_id anomalies during validation