CVE-2026-63852: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.3 enc ring
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/vcn: set nouserfence for VCN v4.0.3 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 ff1a5a125c5a70c328806b9bc01d7d942cf3f9aa)
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Set no_user_fence for the VCN v4.0.3 encoder ring in drm/amdgpu/vcn to reject CS submissions that include user fences.
Linux kernel DRM/amdgpu VCN (VCN v4.0.3 encoder ring) no_user_fence = true
Event History
Frequently Asked Questions
What is the severity of CVE-2026-63852?
CVE-2026-63852 has a severity rating of 7.8, indicating a high risk.
How do I fix CVE-2026-63852?
To mitigate CVE-2026-63852, ensure that you are using an updated version of the Linux kernel where the vulnerability has been patched.
What systems are affected by CVE-2026-63852?
CVE-2026-63852 affects Linux systems that utilize the amdgpu VCN encoder and decoder rings.
What type of vulnerability is CVE-2026-63852?
CVE-2026-63852 is a design flaw that arises from the VCN encoder and decoder rings not supporting 64-bit user fence writes.
What does the term 'no_user_fence' mean in the context of CVE-2026-63852?
In the context of CVE-2026-63852, 'no_user_fence' indicates that the VCN encoder and decoder rings reject command submissions that include user fences.