CVE-2023-52753

What it actually does

Missing NULL check on timing generator pointer before dereferencing its function table in AMD display driver allows local NULL dereference leading to kernel crash.

Why it matters to the business

Affected Linux systems using AMD graphics hardware can experience unexpected kernel crashes and reboots when the display subsystem is exercised, disrupting workloads and availability.

How an attack unfolds

An attacker with local user privileges triggers display timing code paths that leave the timing generator pointer uninitialized or cleared, causing the kernel to dereference NULL and panic.

How to fix it

Update the Linux kernel to a version containing commit 09909f515032fa80b921fd3118efe66b185d10fd or later stable releases that include the NULL check before accessing timing generator functions.

How to confirm the fix worked

Confirm the patch is present by inspecting the drm/amd/display source for the added NULL guard on the timing generator before funcs access; test by exercising display modes on AMD hardware.

Typical attack path

1. Obtain local shell on affected system
2. Exercise or manipulate AMD display timing generator state
3. Trigger NULL pointer access in drm/amd/display code
4. Kernel oops/panic resulting in denial of service

How to detect it

Review kernel logs for NULL pointer dereference oops in amd_display or timing_generator functions; correlate with recent local user activity on systems using AMD display hardware.

What your security team should do

• Prioritize kernel upgrades on all systems with AMD GPUs
• Monitor vendor advisories for backported fixes in distribution kernels
• Restrict unprivileged local access where feasible until patched