---
id: CVE-2026-63851
title: 'drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring

  VCN encoder and decoder rings do not support 64-bit user fence writes,
  reject CS submissions with user fences…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 <
    75091030f07b7957cc0646cd52e2d9d15f611483
  - >-
    Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 <
    6d9a98c5ed65ba92a09e4ca5a5f6941448145529
  - >-
    Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 <
    7f23b5c420b9f68a210c29c5123bace670aa8cc9
  - >-
    Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 <
    589a254bf3e88204c8402b9cbccd5e23a0af990f
  - Linux 6.7
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:32:12.926924Z'
published: '2026-07-19'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:42:07.558Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63851'
references:
  - url: 'https://git.kernel.org/stable/c/75091030f07b7957cc0646cd52e2d9d15f611483'
  - url: 'https://git.kernel.org/stable/c/6d9a98c5ed65ba92a09e4ca5a5f6941448145529'
  - url: 'https://git.kernel.org/stable/c/7f23b5c420b9f68a210c29c5123bace670aa8cc9'
  - url: 'https://git.kernel.org/stable/c/589a254bf3e88204c8402b9cbccd5e23a0af990f'
tags:
  - cve.org
epss: 0.00175
epssPercentile: 0.06559
ingestedAt: '2026-10-16T17:24:46.758Z'
---

## Overview

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

drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring

VCN encoder and decoder rings do not support 64-bit user fence writes,
reject CS submissions with user fences.

(cherry picked from commit 084d94ac93707bdda07efb5cee786f632de4219b)

## Affected

- `Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 < 75091030f07b7957cc0646cd52e2d9d15f611483`
- `Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 < 6d9a98c5ed65ba92a09e4ca5a5f6941448145529`
- `Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 < 7f23b5c420b9f68a210c29c5123bace670aa8cc9`
- `Linux >= 547aad32edac17a3ec4989d8aad2426d0cbeb590 < 589a254bf3e88204c8402b9cbccd5e23a0af990f`
- `Linux 6.7`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.