CVE-2024-46804

What it actually does

Missing validation of msg_id array index in HDCP DDC access path allows out-of-bounds read or write in the Linux kernel DRM/AMD display driver.

Why it matters to the business

Linux systems using AMD graphics hardware face elevated risk of kernel crashes, denial of service, or potential privilege escalation until systems are updated; high prevalence of the kernel in servers, desktops, and embedded devices amplifies exposure across the ecosystem.

How an attack unfolds

An attacker supplies a crafted or invalid msg_id value to the HDCP DDC handling code; because the index is not validated, the kernel performs an array access beyond allocated bounds, enabling memory corruption that can be leveraged for code execution or system instability.

How to fix it

Apply the upstream fix by updating to Linux kernel commit 2a63c90c7a90ab2bd23deebc2814fc5b52abf6d2 or later stable releases that include the array index validation for msg_id; rebuild and deploy the patched kernel across affected systems; verify golang.org/x/net dependencies are at 0.0.0-20180816102801-aaf60122140d or newer if present in the build environment.

How to confirm the fix worked

Confirm the presence of the index validation check in the drm/amd/display source after applying the patch; run static analysis tools such as Coverity to ensure the OVERRUN warning is resolved; test HDCP DDC functionality under boundary conditions on AMD hardware.

Typical attack path

1. Identify target systems running vulnerable Linux kernel versions with AMD display hardware
2. Trigger the HDCP DDC code path through local application or crafted display-related input
3. Supply out-of-range msg_id value to bypass missing bounds check
4. Achieve out-of-bounds memory access leading to corruption or information leak
5. Escalate to kernel-level control or cause denial of service

How to detect it

Review kernel logs for unexpected crashes or warnings originating from the amd display or hdcp ddc modules; inspect audit logs for unusual access patterns to display-related sysfs or device nodes; correlate with any reported out-of-bounds access faults after the published date.

What your security team should do

• Prioritize kernel updates on all AMD graphics-equipped Linux hosts within the next maintenance window
• Monitor EPSS and threat intelligence feeds for any increase in exploitation activity
• Restrict untrusted local access and display configuration changes until patches are deployed
• Incorporate bounds-checking static analysis into the kernel build pipeline