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GHSA-V5JV-J5CW-GGJQ

Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-09-17 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

ntfs: validate usa_ofs before preserving the update sequence number

When ntfs_mft_record_alloc() reuses a free mft record it reads the old update sequence number straight from the on-disk record:

 usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs));

Here m points into the raw $MFT page-cache folio, which still holds unvalidated, MST-protected bytes: the folio is read by a plain iomap_read_folio() and neither post_read_mst_fixup() nor ntfs_mft_record_check() has run on it (both work on private copies). m->usa_ofs is therefore an untrusted u16, and a corrupted record can put it past the end of the record so the two-byte read lands outside the folio. Reading such a record while creating a file gives, under KASAN:

BUG: KASAN: use-after-free in ntfs_mft_record_alloc+... Read of size 2 at addr ... ntfs_mft_record_alloc -> __ntfs_create -> ntfs_create -> path_openat

Only preserve the old update sequence number when usa_ofs is even and in range, mirroring the check ntfs_mft_record_check() already applies; otherwise leave usn zero, which the existing restore below skips.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-90117"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-17T17:17:03Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: validate usa_ofs before preserving the update sequence number\n\nWhen ntfs_mft_record_alloc() reuses a free mft record it reads the old\nupdate sequence number straight from the on-disk record:\n\n     usn = *(__le16 *)((u8 *)m + le16_to_cpu(m-\u003eusa_ofs));\n\nHere m points into the raw $MFT page-cache folio, which still holds\nunvalidated, MST-protected bytes: the folio is read by a plain\niomap_read_folio() and neither post_read_mst_fixup() nor\nntfs_mft_record_check() has run on it (both work on private copies).\nm-\u003eusa_ofs is therefore an untrusted u16, and a corrupted record can put\nit past the end of the record so the two-byte read lands outside the\nfolio.  Reading such a record while creating a file gives, under KASAN:\n\n   BUG: KASAN: use-after-free in ntfs_mft_record_alloc+...\n   Read of size 2 at addr ...\n    ntfs_mft_record_alloc -\u003e __ntfs_create -\u003e ntfs_create -\u003e path_openat\n\nOnly preserve the old update sequence number when usa_ofs is even and in\nrange, mirroring the check ntfs_mft_record_check() already applies;\notherwise leave usn zero, which the existing restore below skips.",
  "id": "GHSA-v5jv-j5cw-ggjq",
  "modified": "2026-09-17T18:31:51Z",
  "published": "2026-09-17T18:31:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90117"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/81684340963da2e898eabb8c1e274433d9375bc6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ea5a3c30710710c1dc5e483d3313309ec2e868f7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-90117 (GCVE-0-2026-90117)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:06 – Updated: 2026-09-17 16:06

Title

ntfs: validate usa_ofs before preserving the update sequence number

Summary

In the Linux kernel, the following vulnerability has been resolved: ntfs: validate usa_ofs before preserving the update sequence number When ntfs_mft_record_alloc() reuses a free mft record it reads the old update sequence number straight from the on-disk record: usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs)); Here m points into the raw $MFT page-cache folio, which still holds unvalidated, MST-protected bytes: the folio is read by a plain iomap_read_folio() and neither post_read_mst_fixup() nor ntfs_mft_record_check() has run on it (both work on private copies). m->usa_ofs is therefore an untrusted u16, and a corrupted record can put it past the end of the record so the two-byte read lands outside the folio. Reading such a record while creating a file gives, under KASAN: BUG: KASAN: use-after-free in ntfs_mft_record_alloc+... Read of size 2 at addr ... ntfs_mft_record_alloc -> __ntfs_create -> ntfs_create -> path_openat Only preserve the old update sequence number when usa_ofs is even and in range, mirroring the check ntfs_mft_record_check() already applies; otherwise leave usn zero, which the existing restore below skips.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/ea5a3c30710710c1d…
https://git.kernel.org/stable/c/81684340963da2e89…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 495e90fa334828d4119061e2726af51d0a0fb4ed , < ea5a3c30710710c1dc5e483d3313309ec2e868f7 (git) Affected: 495e90fa334828d4119061e2726af51d0a0fb4ed , < 81684340963da2e898eabb8c1e274433d9375bc6 (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/mft.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ea5a3c30710710c1dc5e483d3313309ec2e868f7",
              "status": "affected",
              "version": "495e90fa334828d4119061e2726af51d0a0fb4ed",
              "versionType": "git"
            },
            {
              "lessThan": "81684340963da2e898eabb8c1e274433d9375bc6",
              "status": "affected",
              "version": "495e90fa334828d4119061e2726af51d0a0fb4ed",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/mft.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": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "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: validate usa_ofs before preserving the update sequence number\n\nWhen ntfs_mft_record_alloc() reuses a free mft record it reads the old\nupdate sequence number straight from the on-disk record:\n\n     usn = *(__le16 *)((u8 *)m + le16_to_cpu(m-\u003eusa_ofs));\n\nHere m points into the raw $MFT page-cache folio, which still holds\nunvalidated, MST-protected bytes: the folio is read by a plain\niomap_read_folio() and neither post_read_mst_fixup() nor\nntfs_mft_record_check() has run on it (both work on private copies).\nm-\u003eusa_ofs is therefore an untrusted u16, and a corrupted record can put\nit past the end of the record so the two-byte read lands outside the\nfolio.  Reading such a record while creating a file gives, under KASAN:\n\n   BUG: KASAN: use-after-free in ntfs_mft_record_alloc+...\n   Read of size 2 at addr ...\n    ntfs_mft_record_alloc -\u003e __ntfs_create -\u003e ntfs_create -\u003e path_openat\n\nOnly preserve the old update sequence number when usa_ofs is even and in\nrange, mirroring the check ntfs_mft_record_check() already applies;\notherwise leave usn zero, which the existing restore below skips."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-17T16:06:22.705Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ea5a3c30710710c1dc5e483d3313309ec2e868f7"
        },
        {
          "url": "https://git.kernel.org/stable/c/81684340963da2e898eabb8c1e274433d9375bc6"
        }
      ],
      "title": "ntfs: validate usa_ofs before preserving the update sequence number",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90117",
    "datePublished": "2026-09-17T16:06:22.705Z",
    "dateReserved": "2026-09-11T19:38:34.787Z",
    "dateUpdated": "2026-09-17T16:06:22.705Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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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.

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GHSA-V5JV-J5CW-GGJQ

CVE-2026-90117 (GCVE-0-2026-90117)

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