Linux Kernel AMDGPU VCN 5.0.0 User Fence Vulnerability

A vulnerability in the Linux kernel's AMDGPU VCN 5.0.0 encoder and decoder rings has been addressed. These rings do not support 64-bit user fence writes, leading to a rejection of command submissions that include user fences. The vulnerability has been fixed by disabling user fence support for the VCN 5.0.0 encoding ring.

Impact

Exploitation of this vulnerability could disrupt command submission processes that rely on user fences, potentially leading to issues in video encoding or decoding tasks that use the affected VCN 5.0.0 rings.

Reproduction

The vulnerability can be reproduced by attempting to submit a command stream that includes a 64-bit user fence write to the VCN 5.0.0 encoder or decoder ring. The command submission will be rejected, highlighting the lack of support for user fences in this version.

Remediation

Users can update to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for downloading the patched kernel can be found on the official Linux kernel website.