{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89674",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-89674"
  ],
  "published": "2026-09-11T19:47:07Z",
  "summary": "nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget\n\nThe XDR buffer size calculation in nfsd4_ff_encode_layoutget() has\nmultiple errors that can result in either an out-of-bounds write or\nleaking uninitialized kernel memory to the client:\n\n - fh_len doesn't account for XDR padding on the file handle data\n - uid and gid lengths use \"8 + len\" but xdr_encode_opaque() actually\n   writes \"4 + xdr_align_size(len)\" bytes\n - ds_len omits the flags and stats_collect_hint fields (8 bytes),\n   while len's header constant overestimates by 8 bytes -- these\n   partially cancel but leave a net mismatch\n\nThe worst case occurs with short strings (e.g. uid=0, gid=0 with an\nodd-sized file handle), where the function writes up to 5 bytes past\nthe reserved XDR buffer. Conversely, when string lengths happen to be\n4-byte aligned, the reservation is too large and stale buffer content\nis sent to the client.\n\nFix this by breaking out every encoded field explicitly in the ds_len\ncalculation, using xdr_align_size() for all variable-length opaque\nfields, and correcting the header constants.",
  "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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-89674"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3a7fd224df0fbb42167eb1b77be45d72fe0b1098"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/29e4478e2ed5a227e8f0c33cacb91bf227cedd47"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/65a72b721943618eeb3a41c8b36e915591f3f83f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bee826c00ac900473f91306f1f3e5a5a81fd4a74"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e7d9d23ecd9172f05b09bb678ff22db8e361c428"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0380129b1373c437eb35401a174671c8888f4b80"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c81cef6a805dec266c10fc4f83c93d6fcf1a2b43"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f9868174af49d207fbaf0c5e055d088a983684af"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-14T12:06:03Z"
  }
}