CVE-2026-31571

/// Technical description

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

drm/i915: Unlink NV12 planes earlier

unlink_nv12_plane() will clobber parts of the plane state

potentially already set up by plane_atomic_check(), so we

must make sure not to call the two in the wrong order.

The problem happens when a plane previously selected as

a Y plane is now configured as a normal plane by user space.

plane_atomic_check() will first compute the proper plane

state based on the userspace request, and unlink_nv12_plane()

later clears some of the state.

This used to work on account of unlink_nv12_plane() skipping

the state clearing based on the plane visibility. But I removed

that check, thinking it was an impossible situation. Now when

that situation happens unlink_nv12_plane() will just WARN

and proceed to clobber the state.

Rather than reverting to the old way of doing things, I think

it's more clear if we unlink the NV12 planes before we even

compute the new plane state.

(cherry picked from c

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References