{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89965",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-89965"
  ],
  "published": "2026-09-16T10:32:03Z",
  "summary": "nvdimm/btt: reject an arena whose nfree is below the lane count",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvdimm/btt: reject an arena whose nfree is below the lane count\n\nThe BTT info block's nfree field, the number of reserve free blocks, is\nread from the medium without validation.  btt_freelist_init() and\nbtt_rtt_init() size the per-lane freelist[] and rtt[] arrays by nfree,\nbut the I/O path indexes them by the lane from nd_region_acquire_lane(),\nwhich is bounded by nd_region->num_lanes (ND_MAX_LANES), not by nfree.\nA crafted or foreign arena whose nfree is below the lane count makes\nfreelist[lane]/rtt[lane] run past the allocation: an out-of-bounds write.\n\nbtt.rst documents the nlanes = min(nfree, num_cpus) invariant, which the\ncode does not currently honor: num_lanes is ND_MAX_LANES regardless of\nnfree.  Reject an arena whose nfree is below num_lanes at discovery,\nbefore the per-lane arrays are allocated, enforcing that invariant.",
  "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-2026-89965"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/eb491343d2d1784121ad9af91c25b338c28913c3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/59d5cd1f42b4bab3609512c3cb3d3540d3d21da7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f6c5313aae794ecca8f762c1a3493de5c266f120"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f9bf05c63b77d000e9c01f3e47af36973887d350"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6f79d1a5f2611a3d36e9312be5425cd9cb397c51"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6b1faf1f099f7060b5f1f2f0d024132581f1726e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9dfa11cef4750b67591307f2c62e47a23d60e4b7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6a1f2e5ed9267ca19187038ac635393c165213ac"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-16T14:40:32Z"
  }
}