In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v2.5 enc/dec rings VCN encoder and… (CVE-2026-63855)
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v2.5 enc/dec rings VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences. (cherry picked from commit efc9dd5590894109bce9a0bfe1fa5592dd6b20b1)
AI Analysis
Technical Summary
The Linux kernel AMDGPU driver for VCN v2.5 encoder and decoder rings did not support 64-bit user fence writes, which could lead to improper command submissions. The vulnerability was addressed by setting the no_user_fence flag for these rings, thereby rejecting command submissions that include user fences. This change was incorporated via a specific commit (efc9dd5590894109bce9a0bfe1fa5592dd6b20b1).
Potential Impact
The vulnerability could allow command submissions with unsupported 64-bit user fence writes to the VCN encoder and decoder rings, potentially causing unexpected behavior or instability in the affected driver components. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix has been applied in the Linux kernel by setting no_user_fence for the VCN v2.5 encoder and decoder rings, rejecting unsupported user fence submissions. Users should update their Linux kernel to a version that includes this fix. Patch status is not explicitly confirmed in the provided data; users should consult the official Linux kernel advisories or source repositories for the exact fixed versions and apply updates accordingly.
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v2.5 enc/dec rings VCN encoder and… (CVE-2026-63855)
Description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v2.5 enc/dec rings VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences. (cherry picked from commit efc9dd5590894109bce9a0bfe1fa5592dd6b20b1)
CVSS v3.1
Score 7.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel AMDGPU driver for VCN v2.5 encoder and decoder rings did not support 64-bit user fence writes, which could lead to improper command submissions. The vulnerability was addressed by setting the no_user_fence flag for these rings, thereby rejecting command submissions that include user fences. This change was incorporated via a specific commit (efc9dd5590894109bce9a0bfe1fa5592dd6b20b1).
Potential Impact
The vulnerability could allow command submissions with unsupported 64-bit user fence writes to the VCN encoder and decoder rings, potentially causing unexpected behavior or instability in the affected driver components. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix has been applied in the Linux kernel by setting no_user_fence for the VCN v2.5 encoder and decoder rings, rejecting unsupported user fence submissions. Users should update their Linux kernel to a version that includes this fix. Patch status is not explicitly confirmed in the provided data; users should consult the official Linux kernel advisories or source repositories for the exact fixed versions and apply updates accordingly.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-rjvx-mc7h-2h7x
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63855"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a5d27ac2a4a8d598913093d
Added to database: 07/19/2026, 19:38:20 UTC
Last enriched: 07/19/2026, 20:15:10 UTC
Last updated: 09/02/2026, 22:52:13 UTC
Views: 55
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