FKIE_CVE-2026-90200

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-17 17:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix integer overflow in MFT cluster validation In ntfs_init_from_boot(), the boot sector's MFT cluster numbers are validated against the volume size with: if (mlcn * sct_per_clst >= sectors || mlcn2 * sct_per_clst >= sectors) goto out; mlcn and mlcn2 are u64 fields read directly from the boot sector. sct_per_clst is bounded above by 4096 (true_sectors_per_clst() plus the is_power_of_2() check below it), but the multiplication is done in u64 and wraps when mlcn (or mlcn2) is large enough -- e.g. mlcn near 2^62 with sct_per_clst == 4 wraps to 0, which compares below any non-zero 'sectors', so the check is bypassed and the malformed record is accepted. The accepted mlcn is then used unchanged in sbi->mft.lbo = mlcn << cluster_bits; In practice the resulting reads fail at the block layer (sb_bread() returns NULL via grow_buffers()'s check_mul_overflow() guard), so today this manifests as mount failing in odd places rather than as something more dangerous, but the validation step is still wrong and there is no reason for callers to rely on the block layer to catch a value that should never have been accepted in the first place. Use check_mul_overflow() to compute the two sector positions and fail the mount if either multiplication wraps; this preserves the existing semantics (mlcn * sct_per_clst >= sectors) instead of switching to division (mlcn >= sectors / sct_per_clst), which would tighten the check at edge cases where 'sectors' is not a multiple of sct_per_clst. The check_*_overflow() style is the one ntfs3 already uses for similar on-disk arithmetic in fs/ntfs3/run.c.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/169383d8914b8fe03464a83540b5b6de3e7831af
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/805cc5554b13d045dce9b03c13eaf015418739fd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c510c63873103a5da6a498fe537bdb5d6f8d03a2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/dc6d85de7e2656e56e10ff5ba514f2583a4f612b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f77a8d9fdf58e298b36564a44c27fadc617bdd28
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f77a8d9fdf58e298b36564a44c27fadc617bdd28",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "805cc5554b13d045dce9b03c13eaf015418739fd",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "dc6d85de7e2656e56e10ff5ba514f2583a4f612b",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "169383d8914b8fe03464a83540b5b6de3e7831af",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "c510c63873103a5da6a498fe537bdb5d6f8d03a2",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: fix integer overflow in MFT cluster validation\n\nIn ntfs_init_from_boot(), the boot sector\u0027s MFT cluster numbers are\nvalidated against the volume size with:\n\n\tif (mlcn  * sct_per_clst \u003e= sectors ||\n\t    mlcn2 * sct_per_clst \u003e= sectors)\n\t\tgoto out;\n\nmlcn and mlcn2 are u64 fields read directly from the boot sector.\nsct_per_clst is bounded above by 4096 (true_sectors_per_clst() plus\nthe is_power_of_2() check below it), but the multiplication is done\nin u64 and wraps when mlcn (or mlcn2) is large enough -- e.g. mlcn\nnear 2^62 with sct_per_clst == 4 wraps to 0, which compares below\nany non-zero \u0027sectors\u0027, so the check is bypassed and the malformed\nrecord is accepted.\n\nThe accepted mlcn is then used unchanged in\n\n\tsbi-\u003emft.lbo = mlcn \u003c\u003c cluster_bits;\n\nIn practice the resulting reads fail at the block layer (sb_bread()\nreturns NULL via grow_buffers()\u0027s check_mul_overflow() guard), so\ntoday this manifests as mount failing in odd places rather than as\nsomething more dangerous, but the validation step is still wrong\nand there is no reason for callers to rely on the block layer to\ncatch a value that should never have been accepted in the first\nplace.\n\nUse check_mul_overflow() to compute the two sector positions and\nfail the mount if either multiplication wraps; this preserves the\nexisting semantics (mlcn * sct_per_clst \u003e= sectors) instead of\nswitching to division (mlcn \u003e= sectors / sct_per_clst), which\nwould tighten the check at edge cases where \u0027sectors\u0027 is not a\nmultiple of sct_per_clst.  The check_*_overflow() style is the\none ntfs3 already uses for similar on-disk arithmetic in\nfs/ntfs3/run.c."
    }
  ],
  "id": "CVE-2026-90200",
  "lastModified": "2026-09-17T17:17:14.930",
  "metrics": {},
  "published": "2026-09-17T17:17:14.930",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/169383d8914b8fe03464a83540b5b6de3e7831af"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/805cc5554b13d045dce9b03c13eaf015418739fd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c510c63873103a5da6a498fe537bdb5d6f8d03a2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dc6d85de7e2656e56e10ff5ba514f2583a4f612b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f77a8d9fdf58e298b36564a44c27fadc617bdd28"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.