CVE-2026-90289: drm/amd/display: Resize MST HDCP per-connector arrays to 32

Published Sep 17, 2026

Updated

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Resize MST HDCP per-connector arrays to 32

AMDGPUDMMAXDISPLAYINDEX is 31. It suggest a maximum number of 32 connectors. But the way it's used is like MAXDISPLAYCOUNT. Hence we're off by one with DRM core, which supports a max of 32 connectors.

Rename AMDGPUDMMAXDISPLAYINDEX to AMDGPUDMMAXDISPLAYCOUNT to match its actual use, and increase the size to 32 to match the originally intended size.

Affected Software

1 affected component

Linux Linux kernel

Event History

Sep 17, 2026

CVE Published

via MITRE·04:08 PM

Data Sourced

via MITRE·04:08 PM

Description

Frequently Asked Questions

Which systems are exposed to this issue?

The issue affects the AMD display component in the Linux kernel, specifically systems using MST HDCP with connector handling that can reach the DRM core maximum of 32 connectors.

What condition is required to trigger the flaw?

A system must use enough display connectors for the MST HDCP per-connector arrays to require the 32nd connector entry. The vulnerable allocation was sized for 31 entries despite DRM core supporting up to 32 connectors.

How is the issue fixed?

The fix renames the misleading maximum-index constant to a maximum-count constant and resizes the affected per-connector arrays to 32 entries.