Bug 2502293 (CVE-2026-63853)

Summary: CVE-2026-63853 kernel: drm/amdgpu/vcn: set no_user_fence for VCN v4.0 enc ring
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's AMD GPU Video Core Next (VCN) driver. This vulnerability arises because the VCN encoder and decoder rings, responsible for video processing, do not support 64-bit user fence writes. An attacker could exploit this by submitting command requests that include these unsupported user fences. This would result in the system rejecting the submissions, potentially leading to a denial of service for specific video processing functionalities.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-07-19 15:02:23 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/vcn: set no_user_fence for VCN v4.0 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 fd852c048b46f9825e904a4f3f4538fe9d8827d9)