CVE-2024-43886

What it actually does

Null pointer dereference in resource_log_pipe_topology_update when resource_get_otg_master_for_stream is called on a disconnected eDP stream during display topology changes from Extend to Second Display Only mode.

Why it matters to the business

Causes kernel crashes on Linux systems using AMD display hardware when users switch display configurations, resulting in unexpected downtime and potential loss of unsaved work on affected machines.

How an attack unfolds

An attacker with local access triggers repeated display mode switches involving eDP panels to induce the null dereference and crash the system; no remote or unauthenticated exploitation path exists.

How to fix it

Update the Linux kernel to the fixed commit c36e922a36bdf69765c340a0857ca74092003bee or later stable releases containing the null check in dc_resource.c.

How to confirm the fix worked

Verify the patch is present by checking for the null pointer check in resource_log_pipe_topology_update and confirm no crashes occur during eDP display mode transitions after upgrade.

Typical attack path

1. Obtain local user access on a Linux system with AMD graphics
2. Configure displays in Extend mode with an eDP panel present
3. Switch to Second Display Only mode to invoke the vulnerable code path
4. Trigger repeated switches to cause null pointer dereference and kernel panic

How to detect it

Review kernel logs for oops or panic entries referencing resource_log_pipe_topology_update or amd display drivers during display mode changes; correlate with user-initiated display reconfiguration events.

What your security team should do

• Apply the kernel fix immediately on all AMD-based Linux systems
• Prioritize patching servers and workstations that frequently change display configurations
• Monitor for kernel oops reports involving amd_display after applying updates