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… (CVE-2026-63853)
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)
AI Analysis
Technical Summary
The Linux kernel AMDGPU driver for VCN v4.0 encoder and decoder rings did not support 64-bit user fence writes, which could allow command submissions with user fences that are not properly handled. The vulnerability was fixed by setting the no_user_fence flag for these rings, thereby rejecting command submissions that include user fences. This fix was applied via a commit (fd852c048b46f9825e904a4f3f4538fe9d8827d9) and resolves the issue by preventing unsupported user fence operations.
Potential Impact
The vulnerability could have allowed improper command submissions involving user fences on the VCN v4.0 encoder and decoder rings, potentially leading to unexpected behavior or instability in the AMDGPU driver. The exact impact is not detailed, and no known exploits are reported in the wild.
Mitigation Recommendations
A fix has been applied in the Linux kernel by setting the no_user_fence flag for the affected VCN v4.0 encoder and decoder rings. Users should update to a Linux kernel version that includes this commit to ensure the vulnerability is remediated. Patch status is confirmed by the vendor commit; no additional mitigation is indicated.
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… (CVE-2026-63853)
Description
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)
CVSS v3.1
Score 7.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel AMDGPU driver for VCN v4.0 encoder and decoder rings did not support 64-bit user fence writes, which could allow command submissions with user fences that are not properly handled. The vulnerability was fixed by setting the no_user_fence flag for these rings, thereby rejecting command submissions that include user fences. This fix was applied via a commit (fd852c048b46f9825e904a4f3f4538fe9d8827d9) and resolves the issue by preventing unsupported user fence operations.
Potential Impact
The vulnerability could have allowed improper command submissions involving user fences on the VCN v4.0 encoder and decoder rings, potentially leading to unexpected behavior or instability in the AMDGPU driver. The exact impact is not detailed, and no known exploits are reported in the wild.
Mitigation Recommendations
A fix has been applied in the Linux kernel by setting the no_user_fence flag for the affected VCN v4.0 encoder and decoder rings. Users should update to a Linux kernel version that includes this commit to ensure the vulnerability is remediated. Patch status is confirmed by the vendor commit; no additional mitigation is indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-9vxm-g52p-rp85
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63853"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a5d27ac2a4a8d598913097e
Added to database: 07/19/2026, 19:38:20 UTC
Last enriched: 07/19/2026, 20:15:52 UTC
Last updated: 09/02/2026, 22:52:13 UTC
Views: 53
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