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… (CVE-2026-63849)
A vulnerability in the Linux kernel's AMDGPU driver related to the VCN v5.0.1 encoder and decoder rings has been resolved. The issue involved improper handling of 64-bit user fence writes, which are not supported by these rings. The fix involves setting the no_user_fence flag to reject command submissions that include user fences.
AI Analysis
Technical Summary
The Linux kernel AMDGPU driver for VCN v5.0.1 encoder and decoder rings did not support 64-bit user fence writes, potentially allowing command submissions with user fences that could cause unexpected behavior. The vulnerability was addressed by setting the no_user_fence flag to reject such submissions, preventing unsupported user fence operations. This fix was introduced via a specific commit (e16be95a2c3ee712b142cb27d2dca0b461181359).
Potential Impact
The vulnerability could have allowed unsupported 64-bit user fence writes in the VCN encoder and decoder rings, which might lead to instability or incorrect operation of the graphics driver. However, no known exploits in the wild have been reported, and the exact impact on system security or stability 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 affected VCN v5.0.1 encoder and decoder rings. Users should update to a Linux kernel version that includes this commit to ensure the vulnerability is resolved. Since this is a kernel-level fix, upgrading the kernel to a patched version is the recommended remediation.
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… (CVE-2026-63849)
Description
A vulnerability in the Linux kernel's AMDGPU driver related to the VCN v5.0.1 encoder and decoder rings has been resolved. The issue involved improper handling of 64-bit user fence writes, which are not supported by these rings. The fix involves setting the no_user_fence flag to reject command submissions that include user fences.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel AMDGPU driver for VCN v5.0.1 encoder and decoder rings did not support 64-bit user fence writes, potentially allowing command submissions with user fences that could cause unexpected behavior. The vulnerability was addressed by setting the no_user_fence flag to reject such submissions, preventing unsupported user fence operations. This fix was introduced via a specific commit (e16be95a2c3ee712b142cb27d2dca0b461181359).
Potential Impact
The vulnerability could have allowed unsupported 64-bit user fence writes in the VCN encoder and decoder rings, which might lead to instability or incorrect operation of the graphics driver. However, no known exploits in the wild have been reported, and the exact impact on system security or stability 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 affected VCN v5.0.1 encoder and decoder rings. Users should update to a Linux kernel version that includes this commit to ensure the vulnerability is resolved. Since this is a kernel-level fix, upgrading the kernel to a patched version is the recommended remediation.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-r2qg-mr7w-fwj6
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63849"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27ac2a4a8d5989130945
Added to database: 07/19/2026, 19:38:20 UTC
Last enriched: 07/19/2026, 20:15:15 UTC
Last updated: 07/20/2026, 17:26:47 UTC
Views: 11
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