Bug 2502282 (CVE-2026-63849)

Summary: CVE-2026-63849 kernel: drm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's AMD GPU (Graphics Processing Unit) Video Core Next (VCN) component. This vulnerability arises because the VCN encoder and decoder rings do not properly support 64-bit user fence writes. A local attacker could potentially exploit this by submitting command streams (CS) with user fences, leading to the rejection of these submissions. This could result in a denial of service, preventing legitimate operations of the VCN component.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-19 15:01:50 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 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 e16be95a2c3ee712b142cb27d2dca0b461181359)