{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-63854",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-63854"
  ],
  "published": "2026-07-19T14:05:10Z",
  "summary": "drm/amdgpu/vcn: set no_user_fence for VCN v3.0 enc/dec rings",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v3.0 enc/dec rings\n\nVCN encoder and decoder rings do not support 64-bit user fence writes,\nreject CS submissions with user fences.\n\n(cherry picked from commit 663bed3c7b8b9a7624b0d95d300ddae034ad0614)",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-63854"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e74fc9c72c1ba78d0de0b849f5929c3b39a8e20c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/26c4f38529ac78930c9c4713e16ebc5b689bb0a3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2d6525e7b2504f5bbfe9417cddc1e8da858791dd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b076e45e6f757a2829e80d0144c1b5f201bee5af"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f1e5a6660d7cbf006079126d9babbf0ccf538c6b"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - Exploitation requires issuing DRM_IOCTL_AMDGPU_CS on a local AMDGPU render node (/dev/dri/renderD*); this is a local ioctl path, not a network-reachable interface.\nAC:L - An attacker with render-node access can reliably submit a command stream with AMDGPU_CHUNK_ID_FENCE targeting VCN v3.0 encoder/decoder rings without races or uncontrollable system state.\nPR:L - The vulnerable amdgpu_cs_ioctl path requires only authenticated render-node access (DRM_AUTH|DRM_RENDER_ALLOW), which is available to unprivileged local users on typical Linux systems with AMDGPU hardware.\nUI:N - No victim interaction is required; the attacker directly submits the malformed GPU command stream via ioctl from their own process.\nS:U - The vulnerability operates within the attacker's own AMDGPU/GPU context and does not cross a demonstrated security boundary such as VM escape or IOMMU bypass.\nC:H - Allowing unsupported 64-bit user fence submissions on VCN rings causes GPU-initiated memory writes with incorrect semantics; this class of GPU memory corruption can be leveraged for information disclosure.\nI:H - The bug permits GPU DMA writes to attacker-influenced virtual addresses through malformed user-fence handling, constituting a memory corruption primitive that could enable further exploitation.\nA:H - Malformed fence operations on VCN rings can hang the video engine or trigger GPU reset, causing denial of service affecting graphics and compute availability on the system."
    }
  }
}