In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring VCN encoder and… (CVE-2026-63851)
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence 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)
AI Analysis
Technical Summary
The Linux kernel AMDGPU driver for VCN v4.0.5 encoder and decoder rings did not support 64-bit user fence writes, which could lead to improper handling of command submissions containing user fences. The vulnerability was resolved by setting the no_user_fence flag to reject such submissions, preventing unsupported user fence operations. This fix was applied via a kernel commit (084d94ac93707bdda07efb5cee786f632de4219b). No CVSS score or detailed impact metrics are provided.
Potential Impact
The vulnerability could allow unsupported user fence writes in the VCN encoder and decoder rings, potentially leading to unexpected behavior or instability in the AMDGPU driver. No known exploits are reported in the wild. The exact impact on confidentiality, integrity, or availability is not detailed in the available information.
Mitigation Recommendations
A fix has been applied in the Linux kernel by setting the no_user_fence flag for the VCN v4.0.5 encoder and decoder rings to reject command submissions with user fences. Users should update their Linux kernel to a version that includes this commit to mitigate the vulnerability. Patch status is confirmed by the kernel commit referenced. No additional mitigation steps are indicated.
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring VCN encoder and… (CVE-2026-63851)
Description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set no_user_fence 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)
CVSS v3.1
Score 7.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel AMDGPU driver for VCN v4.0.5 encoder and decoder rings did not support 64-bit user fence writes, which could lead to improper handling of command submissions containing user fences. The vulnerability was resolved by setting the no_user_fence flag to reject such submissions, preventing unsupported user fence operations. This fix was applied via a kernel commit (084d94ac93707bdda07efb5cee786f632de4219b). No CVSS score or detailed impact metrics are provided.
Potential Impact
The vulnerability could allow unsupported user fence writes in the VCN encoder and decoder rings, potentially leading to unexpected behavior or instability in the AMDGPU driver. No known exploits are reported in the wild. The exact impact on confidentiality, integrity, or availability is not detailed in the available information.
Mitigation Recommendations
A fix has been applied in the Linux kernel by setting the no_user_fence flag for the VCN v4.0.5 encoder and decoder rings to reject command submissions with user fences. Users should update their Linux kernel to a version that includes this commit to mitigate the vulnerability. Patch status is confirmed by the kernel commit referenced. No additional mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-jcqr-j666-39jw
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63851"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a5d27ac2a4a8d598913094b
Added to database: 07/19/2026, 19:38:20 UTC
Last enriched: 07/19/2026, 20:15:20 UTC
Last updated: 09/02/2026, 22:52:13 UTC
Views: 54
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