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GHSA-XGPR-MX9Q-9VXW

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-13 09:32

Details

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

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89614"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:46Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: bound the free-cluster bitmap scan to the volume\n\nvol-\u003elcn_empty_bits_per_page is sized from vol-\u003enr_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\u0027s 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.",
  "id": "GHSA-xgpr-mx9q-9vxw",
  "modified": "2026-09-13T09:32:23Z",
  "published": "2026-09-11T21:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89614"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/19cac7902a8ab748e15f98ddaafcf5f8882be21d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dc15a9f5307d5372aef3b64bf3ed7802f530c471"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89614 (GCVE-0-2026-89614)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:45 – Updated: 2026-10-19 08:49

Title

ntfs: bound the free-cluster bitmap scan to the volume

Summary

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

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6643 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/dc15a9f5307d5372a…
https://git.kernel.org/stable/c/19cac7902a8ab748e…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 11ccc9107dc460de28af90fac1f42404d9802735 , < dc15a9f5307d5372aef3b64bf3ed7802f530c471 (git) Affected: 11ccc9107dc460de28af90fac1f42404d9802735 , < 19cac7902a8ab748e15f98ddaafcf5f8882be21d (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/lcnalloc.c",
            "fs/ntfs/runlist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "dc15a9f5307d5372aef3b64bf3ed7802f530c471",
              "status": "affected",
              "version": "11ccc9107dc460de28af90fac1f42404d9802735",
              "versionType": "git"
            },
            {
              "lessThan": "19cac7902a8ab748e15f98ddaafcf5f8882be21d",
              "status": "affected",
              "version": "11ccc9107dc460de28af90fac1f42404d9802735",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/lcnalloc.c",
            "fs/ntfs/runlist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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-\u003elcn_empty_bits_per_page is sized from vol-\u003enr_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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - fs/ntfs registers ntfs_export_ops, so nfsd/ksmbd VFS writes on an exported NTFS volume reach ntfs_file_write_iter-\u003eiomap-\u003entfs_attr_expand-\u003entfs_cluster_alloc, and reads reach ntfs_mapping_pairs_decompress, without local shell access.\nAC:L - A crafted image whose $Bitmap covers more clusters than nr_clusters, plus a file run whose LCN sits in that gap, deterministically drives the allocator to index past lcn_empty_bits_per_page and the decoder to accept out-of-volume LCNs, with no race or victim-specific layout.\nPR:N - Triggering needs only permission to cause server-side parse or extend of mounted NTFS metadata (guest/anonymous SMB, a permissive NFS export, or an unprivileged local open/write on an already-mounted volume), not init-namespace root or CAP_SYS_ADMIN at trigger time.\nUI:N - After the crafted volume is mounted and optionally exported, ordinary remote or local write/truncate/fallocate, and reads that decompress mapping pairs, trigger the bug; no extra victim mount dialog, USB insertion, or confirmation is required during the attack.\nS:U - Slab out-of-bounds access to vol-\u003elcn_empty_bits_per_page and misdirected block I/O remain in the host kernel/OS security domain and do not cross a VM, container, or IOMMU boundary to another authority.\nC:H - ntfs_cluster_alloc performs a KASAN-confirmed slab out-of-bounds read of lcn_empty_bits_per_page at an attacker-influenced page index, and decoded LCNs past nr_clusters make iomap reads disclose data beyond the NTFS volume, a kernel heap/OOB-read disclosure primitive.\nI:H - With zone_end set from the poisoned LCN, the bitmap scan calls ntfs_set_lcn_empty_bits() on out-of-range indices (heap OOB write of empty-bit counts) and iomap can write past the volume using those LCNs, a kernel memory-corruption primitive consistent with privilege escalation.\nA:H - KASAN reports a slab out-of-bounds access when a file on such a volume is extended; indexing past the kvmalloc array can oops, and the OOB write of lcn_empty_bits_per_page can panic or hang the host, so even failed exploitation denies service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:49:46.853Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/dc15a9f5307d5372aef3b64bf3ed7802f530c471"
        },
        {
          "url": "https://git.kernel.org/stable/c/19cac7902a8ab748e15f98ddaafcf5f8882be21d"
        }
      ],
      "title": "ntfs: bound the free-cluster bitmap scan to the volume",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89614",
    "datePublished": "2026-09-11T19:45:14.747Z",
    "dateReserved": "2026-09-11T19:38:34.735Z",
    "dateUpdated": "2026-10-19T08:49:46.853Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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