Linux Kernel AMDGPU VCN 3.0 User Fence Vulnerability

A vulnerability in the Linux kernel's AMDGPU driver for VCN 3.0 has been addressed. The issue arose because the VCN encoder and decoder rings do not allow 64-bit user fence writes, leading to a rejection of command submissions that include user fences. This vulnerability was present in the Linux kernel stable tree.

Impact

The vulnerability could cause issues with command submission in the VCN 3.0 encoder and decoder rings, potentially leading to application or system-level performance problems.

Reproduction

To reproduce this vulnerability, attempt to submit a command to the VCN 3.0 encoder or decoder ring that includes a 64-bit user fence write. The command submission will be rejected, indicating that the user fence write is not supported.

Remediation

The vulnerability has been fixed in the Linux kernel. Users should upgrade to the latest version of the stable Linux kernel to apply the patch.