Linux Kernel AMD Graphics Driver DML21 Plane ID Handling Vulnerability

A vulnerability in the Linux kernel's AMD graphics driver has been addressed. The issue arose in the Display Component's DML21 (Display Machine Language) processing, where the stream ID was not properly validated before retrieving the plane ID. This oversight could lead to incorrect warnings during a mode1 reset operation. The vulnerability was linked to several kernel modules, including amdgpu, and was triggered by the DML2 resource management process, which is part of the AMD GPU's display pipeline management.

Impact

The vulnerability could cause false positive warnings during the AMD GPU recovery process, potentially leading to incorrect handling of display resources.

Reproduction

The vulnerability can be reproduced by performing a mode1 reset on a system with an affected version of the Linux kernel and the AMD graphics driver. This can be done by writing to the AMD GPU recovery debugfs file, which will trigger the DML2 resource management process. The resulting false positive warning can be observed in the kernel log.

Remediation

Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for upgrading the kernel can be found in the official Ubuntu documentation.