SB20260720413 - Improper input validation in Linux kernel amd amdgpu driver

Description

This security bulletin contains information about 1 vulnerability.

1) Improper input validation (CVE-ID: CVE-2026-63853)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper input validation in the VCN v4.0 encoder ring submission handling when processing command submissions with user fences. A local user can submit a crafted command stream with a user fence to cause a denial of service.

The issue affects VCN v4.0 encoder functionality, and stems from unsupported 64-bit user fence writes being accepted.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1286b6872de0aee1feeeaa6dbac86369806de9a5
• https://git.kernel.org/stable/c/51f694221047c84fa185be98210eb2c354ffb8c6
• https://git.kernel.org/stable/c/6bdd2ed6458d35c368fbe9550a4d7f342abd3a92