CVE-2026-63851: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/vcn: set nouserfence 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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
For the VCN v4.0.5 encoder ring in drm/amdgpu/vcn, set no_user_fence to prevent 64-bit user fence writes, and reject CS submissions that include user fences.
drm/amdgpu/vcn no_user_fence for VCN v4.0.5 enc ring = set
Event History
Frequently Asked Questions
What is the severity of CVE-2026-63851?
The severity of CVE-2026-63851 is rated high with a score of 7.8.
How do I fix CVE-2026-63851?
To fix CVE-2026-63851, update to the latest version of the Linux kernel that addresses this vulnerability.
What systems are affected by CVE-2026-63851?
CVE-2026-63851 affects systems running the Linux kernel with VCN v4.0.5 encoder and decoder rings.
What types of vulnerabilities does CVE-2026-63851 include?
CVE-2026-63851 includes vulnerabilities related to the handling of 64-bit user fence writes in AMD GPU encoders.
Is user data compromised in CVE-2026-63851?
Yes, CVE-2026-63851 can potentially compromise user data, as it impacts the integrity of the graphics processing functions.