CVE-2026-68272

Technical Description

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

drm/amdgpu: validate CP_GFX_SHADOW chunk size in CS pass1

Add a minimum-length check for the AMDGPU_CHUNK_ID_CP_GFX_SHADOW chunk in

amdgpu_cs_pass1(), matching the gate already present for the IB, FENCE and

BO_HANDLES chunk types.

The CP_GFX_SHADOW case previously shared a bare break with the dependency

and syncobj chunk types, which do not dereference a fixed-size struct. When

userspace submits this chunk with length_dw == 0, vmemdup_array_user() is

called with size 0 and returns ZERO_SIZE_PTR, which passes the IS_ERR()

check. amdgpu_cs_p2_shadow() then dereferences chunk->kdata as a struct

drm_amdgpu_cs_chunk_cp_gfx_shadow (reading shadow->flags), faulting on the

ZERO_SIZE_PTR and causing a NULL-pointer dereference.

This is reachable by an unprivileged process in the render group. Reject

undersized chunks with -EINVAL during pass1 so the bad submission is

rejected before pass2 ever dereferences the data.

(cherry

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