CVE-2024-47704

What it actually does

Null pointer dereference in dp_enable_link_phy and dp_disable_link_phy when link_res->hpo_dp_link_enc is uninitialized, reported as FORWARD_NULL issues.

Why it matters to the business

Potential kernel instability or denial of service on systems using affected AMD display hardware; high ecosystem prevalence increases exposure across dependent environments, with remediation urgency driven by 715 days since publication.

How an attack unfolds

An attacker with local access triggers display link enable/disable paths that pass an uninitialized hpo_dp_link_enc pointer, leading to a crash; listed threat actors in Linux kernel resource and access issues indicate possible use in espionage or financially motivated campaigns.

How to fix it

Upgrade the Linux kernel to the fixed commit 8c22a62288194f072eb3a51045b700fce1c18d9e or later stable releases containing the null check; apply vendor-supplied kernel updates promptly given the publication age and prevalence.

How to confirm the fix worked

Confirm kernel version includes the referenced commit; review source for the added null check on link_res->hpo_dp_link_enc in the affected display functions; test display link operations under load.

Typical attack path

1. Obtain local user access on a vulnerable Linux system with AMD display hardware
2. Trigger dp_enable_link_phy or dp_disable_link_phy code paths without prior hpo_dp_link_enc initialization
3. Cause null dereference resulting in kernel fault or crash

How to detect it

Search kernel logs for null pointer dereference oops in amd/display or drm modules; examine crash dumps for references to dp_enable_link_phy or dp_disable_link_phy; correlate with display reconfiguration events.

What your security team should do

• Prioritize kernel updates on all AMD GPU systems due to extended time since disclosure
• Monitor for related kernel oops or display driver crashes as potential indicators
• Review downstream dependents for inherited exposure