CVE-2026-89611 (GCVE-0-2026-89611)
Vulnerability from cvelistv5
Published
2026-09-11 19:45
Modified
2026-10-19 08:49
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: ntfs: validate non-resident attribute offsets ntfs_attr_update_meta() shifts the attribute name when converting between non-sparse and sparse attributes. Converting to sparse also adds the compressed_size field before the name and mapping pairs, requiring eight additional bytes in the attribute record. However, the validator does not check that name_offset is within safe boundaries for these operations or that the additional space is available. A malicious MFT record could set name_offset such that: 1. The name is positioned at the very end of a non-sparse attribute. Converting to sparse would shift the name forward by 8 bytes, writing beyond the attribute boundary. 2. The name overlaps with the mapping pairs, causing corruption during conversion. Add validation to ensure: - For named attributes, name_offset is within valid bounds - Name does not extend beyond the attribute or overlap with mapping pairs - For non-sparse, non-compressed attributes, eight bytes are available after mapping_pairs_offset for the compressed_size field The space check also covers unnamed attributes, for which name_offset = 0 is valid and no name range needs to be checked.
Impacted products
Vendor Product Version
Linux Linux Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 0   ≤
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/attrib.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cd7b3dc7557faadeea626034e3bac68a449851ef",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "a83e82b0ec3ae523028e24813f23f18b43e8fc1c",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "7.2.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/attrib.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "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",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: validate non-resident attribute offsets\n\nntfs_attr_update_meta() shifts the attribute name when converting between\nnon-sparse and sparse attributes. Converting to sparse also adds the\ncompressed_size field before the name and mapping pairs, requiring eight\nadditional bytes in the attribute record.\n\nHowever, the validator does not check that name_offset is within safe\nboundaries for these operations or that the additional space is available.\nA malicious MFT record could set name_offset such that:\n\n1. The name is positioned at the very end of a non-sparse attribute.\n   Converting to sparse would shift the name forward by 8 bytes,\n   writing beyond the attribute boundary.\n\n2. The name overlaps with the mapping pairs, causing corruption during\n   conversion.\n\nAdd validation to ensure:\n- For named attributes, name_offset is within valid bounds\n- Name does not extend beyond the attribute or overlap with mapping pairs\n- For non-sparse, non-compressed attributes, eight bytes are available\n  after mapping_pairs_offset for the compressed_size field\n\nThe space check also covers unnamed attributes, for which name_offset = 0\nis valid and no name range needs to be checked."
        }
      ],
      "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 ksmbd/nfsd VFS write, truncate, create, and ksmbd vfs_fallocate(FALLOC_FL_PUNCH_HOLE) on an exported NTFS volume reach ntfs_attr_update_mapping_pairs() \u2192 ntfs_attr_update_meta() without local shell access.\nAC:L - A crafted MFT record with a malicious name_offset or too little mapping-pairs slack makes ntfs_attr_update_meta() memmove the name or add compressed_size on every attacker-driven punch-hole, sparse extend, or directory update; no race or uninfluenced layout is required.\nPR:N - Exploitation needs only write or create access on the mounted NTFS volume, including guest/anonymous SMB or world-writable NFS on a misconfigured export and automounted removable media; no init-namespace root or CAP_SYS_ADMIN is required.\nUI:N - Once the NTFS volume is rw-mounted and optionally exported (or automounted from shared/removable storage), the attacker triggers sparsity conversion via fallocate, truncate, write, or create; no further victim clicks or cooperative opens are needed.\nS:U - The overflow corrupts the kmalloc MFT-record buffer and adjacent host-kernel heap during filesystem metadata updates; this is standard kernel privilege impact, not a VM escape, IOMMU bypass, or sandbox scope change.\nC:H - memmove of the attacker-controlled attribute name and later mapping-pairs builds write past the kmalloc(mft_record_size) slab into neighboring objects, which per kernel CNA guidance yields an information-disclosure primitive from corrupted adjacent heap contents.\nI:H - Converting to or from sparse performs an out-of-bounds heap write of attacker-chosen name bytes and can shift mapping_pairs_offset so ntfs_mapping_pairs_build() stores runs past the record, enabling slab corruption and control-flow hijack.\nA:H - Overflowing the kmalloc MFT-record slab into adjacent memory can oops or panic the kernel, and even failed exploitation leaves inconsistent MFT metadata that crashes later lookups or writeback."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:49:43.569Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cd7b3dc7557faadeea626034e3bac68a449851ef"
        },
        {
          "url": "https://git.kernel.org/stable/c/a83e82b0ec3ae523028e24813f23f18b43e8fc1c"
        }
      ],
      "title": "ntfs: validate non-resident attribute offsets",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89611",
    "datePublished": "2026-09-11T19:45:12.646Z",
    "dateReserved": "2026-09-11T19:38:34.734Z",
    "dateUpdated": "2026-10-19T08:49:43.569Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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