---
id: CVE-2026-63850
title: 'drm/amdgpu/vcn: set no_user_fence for VCN v5.0.0 enc ring'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/amdgpu/vcn: set no_user_fence for VCN v5.0.0 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 >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff <
    9f5a1459ecc3195282be617639d710b54779c9dc
  - >-
    Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff <
    139a8a52ef4349c62129703b3a3e3a6ae4d634eb
  - >-
    Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff <
    2c350f3cd94be847ac216e1358ec7001eaaf0934
  - >-
    Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff <
    8cae0ce77de492d7c31c1532a2e80c0c6e7e58cb
  - Linux 6.9
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:32:10.435791Z'
published: '2026-07-19'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:42:07.415Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63850'
references:
  - url: 'https://git.kernel.org/stable/c/9f5a1459ecc3195282be617639d710b54779c9dc'
  - url: 'https://git.kernel.org/stable/c/139a8a52ef4349c62129703b3a3e3a6ae4d634eb'
  - url: 'https://git.kernel.org/stable/c/2c350f3cd94be847ac216e1358ec7001eaaf0934'
  - url: 'https://git.kernel.org/stable/c/8cae0ce77de492d7c31c1532a2e80c0c6e7e58cb'
tags:
  - cve.org
epss: 0.00175
epssPercentile: 0.06559
ingestedAt: '2026-10-16T17:24:46.760Z'
---

## Overview

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

drm/amdgpu/vcn: set no_user_fence for VCN v5.0.0 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 49b1fbbb5a071197ee71e2d70959b1cb29bdc317)

## Affected

- `Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff < 9f5a1459ecc3195282be617639d710b54779c9dc`
- `Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff < 139a8a52ef4349c62129703b3a3e3a6ae4d634eb`
- `Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff < 2c350f3cd94be847ac216e1358ec7001eaaf0934`
- `Linux >= b6d1a06320519ac3bfda6ce81067a1bc409b9cff < 8cae0ce77de492d7c31c1532a2e80c0c6e7e58cb`
- `Linux 6.9`

## Remediation

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