{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-63846",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-63846"
  ],
  "published": "2026-07-19T14:05:10Z",
  "summary": "drm/amdgpu/jpeg: set no_user_fence for JPEG v3.0 ring",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/jpeg: set no_user_fence for JPEG v3.0 ring\n\nJPEG rings do not support 64-bit user fence writes, reject CS\nsubmissions with user fences.\n\n(cherry picked from commit 4d7d774f100efb5089c86a1fb8c5bf47c63fc9ef)",
  "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-2026-63846"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ee035a9d3eed3a9f5a3e83c31a10b321c9598861"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/303da8279f195cc741adc52c1b44d6b64de63bb0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5ada37d7f736f9feeaa06a25e470a4c74e67a61a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/48ce00787e3fddd2b45692fc991b8ab128343da5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a2baf12eec41f246689e6a3f8619af1200031576"
    }
  ],
  "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 - The vulnerable code is reached only through DRM_IOCTL_AMDGPU_CS on an AMDGPU render node (/dev/dri/renderD*), requiring a local ioctl to submit a command buffer with AMDGPU_CHUNK_ID_FENCE to the JPEG v3.0 decode ring (AMDGPU_HW_IP_VCN_JPEG).\nAC:L - On affected VCN 3.0.x hardware with JPEG v3.0 (e.g. Navi 21/Sienna_Cichlid RX 6000 series), an attacker fully controls CS submission parameters and can reliably trigger the unsupported 64-bit user fence path without races or conditions beyond attacker control.\nPR:L - DRM_IOCTL_AMDGPU_CS is gated by DRM_AUTH|DRM_RENDER_ALLOW, requiring only local access to the render node available to unprivileged users in the render group or equivalent permissions, not root or special capabilities.\nUI:N - Exploitation requires no victim interaction beyond the attacker (or their process) opening the render node and submitting crafted GPU command buffers with user fences.\nS:U - The impact is confined to the attacker's GPU security context (their process VM and GPU mappings); exploitation does not cross VM, container, or IOMMU boundaries to affect other security authorities.\nC:H - The unsupported 64-bit user fence causes the GPU to perform unintended memory writes that can corrupt adjacent GPU-accessible memory, and memory corruption primitives can be leveraged for information disclosure.\nI:H - The GPU writes a fence sequence number via GPCOM to an attacker-influenced GPU virtual address, providing a controlled write primitive that can corrupt GPU memory and potentially be chained for further exploitation.\nA:H - Malformed fence operations on unsupported hardware can hang or fault the GPU subsystem, requiring a GPU reset and denying availability of graphics/compute workloads."
    }
  }
}