CVE-2024-49914

What it actually does

Null pointer dereference in dcn20_program_pipe when pipe_ctx->plane_state is accessed without a prior null check, allowing invalid memory access in the AMD display hardware sequencing code.

Why it matters to the business

Potential kernel panic or system crash on Linux systems using affected AMD display hardware, leading to unplanned downtime and requiring reboots or patches.

How an attack unfolds

An attacker triggers the vulnerable display pipeline setup path in the kernel driver by manipulating display or plane configuration state to reach dcn20_program_pipe with a null plane_state pointer, resulting in dereference.

How to fix it

Apply the upstream kernel patch adding the null check for pipe_ctx->plane_state in dcn20_hwseq.c; upgrade affected packages to nokogiri (RubyGems) 1.8.2 where applicable.

How to confirm the fix worked

Confirm the null check exists before the plane_state access in dcn20_program_pipe and test display initialization paths do not panic under null conditions.

Typical attack path

1. Obtain local or remote access to a system running vulnerable Linux kernel with AMD display support
2. Craft display or graphics operations that invoke dcn20_program_pipe with null plane_state
3. Trigger the code path at line 1925 without the null guard to cause dereference
4. Observe kernel oops or panic from the memory corruption

How to detect it

Review kernel logs for oops or panic messages referencing dcn20_program_pipe and plane_state; inspect call stacks around line 1925 in dcn20_hwseq.c.

What your security team should do

• Prioritize kernel updates on systems with AMD GPUs
• Monitor for kernel oops reports related to dcn20_hwseq
• Apply fixed package versions such as nokogiri 1.8.2 in dependent environments
• Review EPSS stability and absence from KEV for risk acceptance decisions