CVE-2026-89614

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ntfs: bound the free-cluster bitmap scan to the volume vol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but ntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap. Those are independent on-disk quantities and the mount-time check only rejects a $Bitmap that is too small, so an image whose $Bitmap covers more clusters than the volume has lets the scan index past the array. A run whose LCN lies in that gap takes the allocator straight there, since the caller passes the file's own last LCN as its locality hint. KASAN reports a slab out-of-bounds read when a file on such a volume is extended. Clamp the scan to what that array covers, mirroring the max_index calculation the mount-time scan already uses, and reject a decoded LCN at or beyond nr_clusters in the mapping pairs decoder. Conforming volumes are unaffected.

Severity

CRITICAL

CVSS score

9.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11 20:19:46.543000

Last modified

2026-10-19 09:17:58.040000

View original CVE JSON

{
  "id": "CVE-2026-89614",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:46.543",
  "lastModified": "2026-10-19T09:17:58.040",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: bound the free-cluster bitmap scan to the volume\n\nvol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but\nntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap.\nThose are independent on-disk quantities and the mount-time check only\nrejects a $Bitmap that is too small, so an image whose $Bitmap covers more\nclusters than the volume has lets the scan index past the array.  A run\nwhose LCN lies in that gap takes the allocator straight there, since the\ncaller passes the file's own last LCN as its locality hint.  KASAN reports\na slab out-of-bounds read when a file on such a volume is extended.\n\nClamp the scan to what that array covers, mirroring the max_index\ncalculation the mount-time scan already uses, and reject a decoded LCN\nat or beyond nr_clusters in the mapping pairs decoder.  Conforming\nvolumes are unaffected."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/ntfs/lcnalloc.c",
            "fs/ntfs/runlist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "11ccc9107dc460de28af90fac1f42404d9802735",
              "lessThan": "dc15a9f5307d5372aef3b64bf3ed7802f530c471",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "11ccc9107dc460de28af90fac1f42404d9802735",
              "lessThan": "19cac7902a8ab748e15f98ddaafcf5f8882be21d",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/ntfs/lcnalloc.c",
            "fs/ntfs/runlist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7.1",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "7.1",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/19cac7902a8ab748e15f98ddaafcf5f8882be21d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/dc15a9f5307d5372aef3b64bf3ed7802f530c471",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}