CVE-2023-52815

What it actually does

Null pointer dereference in amdgpu_vkms_conn_get_modes when drm_cvt_mode returns NULL, resulting in kernel panic.

Why it matters to the business

Local denial of service that can crash affected Linux systems and interrupt operations until reboot.

How an attack unfolds

A local attacker triggers the amdgpu VKMS connector mode function under conditions where drm_cvt_mode fails, causing an immediate NULL dereference and kernel crash.

How to fix it

Apply the upstream kernel fix that adds an explicit NULL check after the drm_cvt_mode call; rebuild and deploy the patched kernel.

How to confirm the fix worked

Inspect the amdgpu_vkms source to confirm the added NULL guard around the drm_cvt_mode return value; test mode retrieval under failure injection.

Typical attack path

1. Obtain local shell or user access
2. Invoke or exercise the amdgpu_vkms_conn_get_modes code path
3. Force drm_cvt_mode to return NULL
4. Trigger kernel panic via dereference

How to detect it

Search kernel logs and crash dumps for oops or panic messages containing amdgpu_vkms_conn_get_modes or drm_cvt_mode.

What your security team should do

• Prioritize kernel updates on all AMD GPU systems running the vulnerable VKMS driver
• Limit untrusted local accounts where possible
• Monitor for kernel oops reports referencing amdgpu_vkms