CVE-2024-47752

What it actually does

Null pointer dereference in the H264 stateless decoder when the framebuffer pointer is NULL, resulting in a kernel crash due to unhandled memory access in media processing code.

Why it matters to the business

Unexpected system crashes during video decoding operations can disrupt media workflows, reduce availability of affected systems, and require manual intervention or reboots to recover.

How an attack unfolds

An attacker supplies a specially crafted video stream to the stateless H264 decoder that causes the framebuffer to be NULL, triggering the unhandled dereference and kernel panic; listed threat actors have targeted similar Linux kernel memory issues in zero-day campaigns.

How to fix it

Apply the upstream kernel patch resolving the smatch warning in vdec_h264_req_if.c or update to a kernel version containing the fix; monitor for official distribution backports.

How to confirm the fix worked

Confirm the patch is present by reviewing the vdec_h264_req_if.c source for the added NULL check on the framebuffer, or test with crafted inputs that previously triggered the crash.

Typical attack path

1. Identify systems running vulnerable Linux kernel versions with Mediatek VCODEC H264 decoder enabled
2. Deliver malicious H264 content via file, stream, or application input to the decoder
3. Trigger the NULL framebuffer condition during decoding
4. Cause kernel crash and potential denial of service

How to detect it

Review kernel logs for oops or panic entries involving vdec_h264_req_if or framebuffer NULL dereferences; inspect media processing audit trails for unexpected decoder failures.

What your security team should do

• Prioritize kernel updates on systems using Mediatek VCODEC for H264 stateless decoding
• Restrict untrusted video input to decoder components until patched
• Monitor kernel logs for related oops or panic messages during media operations