Linux Kernel AMDGPU VCN User Fence Vulnerability in VCN 5.0.1 Encoder and Decoder Rings

A vulnerability in the Linux kernel's AMDGPU VCN 5.0.1 encoder and decoder rings has been addressed. These rings do not support 64-bit user fence writes, leading to a rejection of command stream submissions that include user fences. The issue has been resolved by modifying the VCN ring functions to disable user fence support, ensuring compatibility with the hardware's capabilities.

Impact

The vulnerability could cause command stream submissions with user fences to be rejected, potentially leading to issues in video encoding or decoding processes that rely on the VCN hardware.