{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-64219",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-64219"
  ],
  "published": "2026-07-24T15:23:26Z",
  "summary": "drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async\n\n[Why&How]\ndc_process_dmub_aux_transfer_async() copies payload->length bytes into a\n16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which\nis a no-op in release builds. If a caller ever passes length > 16 this\nresults in a stack buffer overflow via memcpy.\n\nAdditionally, link_index is used to dereference dc->links[] without\nbounds checking against dc->link_count, risking an out-of-bounds access.\n\nReplace the ASSERT with a hard runtime check that returns false when\npayload->length exceeds the destination buffer size, and add a bounds\ncheck for link_index before it is used.\n\n(cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:H/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": "6.1.175",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-64219"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d6590e3f766e3111dd1beaf88b9384d117acfa6b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/16a5fa57565afb6bf37e18129921c270c93d8e2b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/90c398e822ca76e40548df0c061dd4f93ea92d71"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3265f3ed373fb8048be713aadcdf702579a0e53d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1ecde19bfce6535bffddad1139ff466b6d401b8e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1c8c6e912f2945b2a3e669afca6b52174b88e86e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6c92f6d9600efa3ef0d9e560a2b52776d9803c29"
    }
  ],
  "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": 7.0,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The closest attack surface is the local DRM DisplayPort AUX character-device path; no network protocol reaches this function. Physical USB4/DisplayPort devices can initiate AUX activity but cannot directly supply the vulnerable length or index.\nAC:H - All current callers cap transactions at 16 bytes, while link_index is derived from an internally created dc_link. Exploitation therefore requires an abnormal internal caller or corrupted state that the attacker cannot directly create.\nPR:L - Reaching the relevant DRM/AUX interfaces requires local device access, but the traced path contains no administrative capability or init-namespace privilege check. Basic session or device-ACL access is therefore sufficient.\nUI:N - Once the attacker has local device access and the required abnormal state exists, the vulnerable copy or dereference executes without further victim action.\nS:U - The corruption occurs within the host kernel and does not inherently cross a separate virtualization, IOMMU, or other security authority boundary.\nC:H - A length greater than 40 can copy payload-controlled bytes beyond the 64-byte stack command and overwrite control data. Successful control-flow hijacking would permit arbitrary kernel-memory disclosure.\nI:H - The unbounded stack write can overwrite saved state and potentially enable kernel code execution; an invalid link_index can also dereference a wild pointer. This supports complete integrity impact.\nA:H - FORTIFY converts a sufficiently large copy into a kernel panic, while unfortified stack corruption, stack-canary failure, or the unchecked link dereference can cause an oops or crash."
    }
  }
}