{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89954",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-89954"
  ],
  "published": "2026-09-16T10:32:03Z",
  "summary": "mtd: afs: validate v2 image info bounds",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmtd: afs: validate v2 image info bounds\n\nThe AFS v2 parser uses footer[8] to locate the image information block\ninside the current erase block, then uses the image information\nregion_count to walk entries from a fixed local array. The footer offset\nand region count come from flash contents and are not checked against the\nerase block or the local image-info array before use.\n\nReject v2 entries whose image information offset would underflow the\nerase block calculation, and reject region counts that cannot fit in the\nlocal image-info array before walking region entries.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-89954"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1bec05a68414cf8d0cab6cb42445b8603f32ffc4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3ad8ff12fd44b08af9212ac4883a7e29d2ab7348"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/875daa3c750814ff2e2dc050239c390048f0bcd0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/da740539e8f370767317e24615349b9342a6e773"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1edea8900ca3e405c1421d8b5c29f97107874f72"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/18916f475057cbd2fb8ea6ae86e6b85884ad1d53"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d14e6298139f58a87a87d7022e26a7f37f0ddce7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e9290031f736e99ad17c25c00311c92c266843b7"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-16T14:40:32Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.0,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The AFS v2 parser runs from parse_mtd_partitions() during local MTD/physmap probe, reading on-flash ARM Firmware Suite footers via mtd_read(); no network protocol, Bluetooth/Wi-Fi path, or USB gadget/host handler invokes this code.\nAC:L - An attacker who controls the flash image can plant valid AFS v2 magic and CRC and set footer[8] and region_count arbitrarily, so the unsigned info-block offset and the region walk run deterministically with no race or layout condition outside attacker control.\nPR:N - parse_afs_partitions() runs automatically at boot/probe on affected ARM/physmap systems with no credential or capability check; crafted AFS metadata can be delivered in firmware/OTA/supply-chain flash contents without a local OS account.\nUI:N - Partition parsing runs as part of MTD driver initialization at boot or bind; no separate victim action such as mounting a filesystem or opening a device node is required.\nS:U - The stack over-read and any resulting oops remain inside the host kernel; this is not a VM escape, IOMMU bypass, or sandbox breakout.\nC:H - Attacker-controlled region_count drives an unbounded read past the on-stack imginfo[36] array, and kstrdup() of a possibly non-NUL-terminated footer name can copy that kernel stack/adjacent memory into a partition name far beyond a small bounded leak.\nI:L - OOB-derived region offset/size and repeated kstrdup() results are stored in the registered mtd_partition object, modifying kernel flash-layout metadata, but the loop does not perform an out-of-bounds write or yield a control-flow hijack primitive.\nA:H - Walking region_count past imginfo[] reaches unmapped stack or vmalloc pages and oopses or panics the kernel; a huge count can also livelock probe and exhaust memory via kstrdup in the loop."
    }
  }
}