The Linux kernel's AMD GPU display driver used a constant AMDGPU_DM_MAX_DISPLAY_INDEX set to 31, implying a maximum of 32 connectors. However, this constant was used inconsistently as a maximum count rather than a maximum index, causing an off-by-one error in the handling of MST HDCP per-connector arrays. The fix involved renaming the constant to AMDGPU_DM_MAX_DISPLAY_COUNT to reflect its actual use and increasing the array size to 32 to align with the intended maximum number of connectors. This correction prevents potential out-of-bounds access in the DRM core subsystem.

This vulnerability could allow local attackers with limited privileges to cause memory corruption or other unintended behavior in the AMD GPU display driver, potentially leading to confidentiality, integrity, and availability impacts as indicated by the CVSS vector (C:H/I:H/A:H). There is no indication of known exploits in the wild.

A fix has been implemented in the Linux kernel to rename the constant and increase the array size to prevent off-by-one errors. Users should apply the official Linux kernel updates that include this fix. Since this is a kernel-level vulnerability, updating to the patched kernel version is the recommended remediation. Patch status is not explicitly stated in the input data; therefore, check the vendor advisory for the exact fixed kernel versions and apply updates accordingly.