CVE-2026-90199 (GCVE-0-2026-90199)
Vulnerability from cvelistv5
Published
2026-09-17 16:07
Modified
2026-10-19 08:59
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: reject out-of-range evcn in mi_enum_attr() In mi_enum_attr(), the start/end VCN validation for non-resident attributes is: if (svcn > evcn + 1) goto out; When evcn is U64_MAX the "evcn + 1" expression wraps to 0 and any svcn passes the check. For evcn values close to U64_MAX (but not equal to it) the right-hand side is still a meaningless near-wrap upper bound, so a malformed on-disk attribute with svcn == 0 and evcn near U64_MAX can pass mi_enum_attr() unrejected. VCN (virtual cluster number) is a cluster index, so any valid evcn is bounded by the volume's total cluster count, which ntfs3 holds in sbi->used.bitmap.nbits (set up in ntfs_init_from_boot() before any caller of mi_enum_attr() runs). Reject evcn values that fall outside this range. However, an empty non-resident attribute (no allocated clusters) is legitimately encoded with svcn == 0 and evcn == -1 (U64_MAX), e.g. via attr->nres.evcn = cpu_to_le64((u64)vcn - 1) with vcn == 0. That sentinel must keep passing, so exclude evcn == U64_MAX from the range check. The existing "svcn > evcn + 1" test still tolerates the sentinel ("0 > 0" is false) and continues to require svcn == 0 for it, while the range check rejects every other out-of-range evcn and thereby also defuses the "evcn + 1" wraparound. svcn does not need its own bound: once evcn < nbits, "svcn > evcn + 1" implies svcn <= nbits. [almaz.alexandrovich@paragon-software.com: fixed evcn check]
References
Impacted products
Vendor Product Version
Linux Linux Version: 013ff63b649475f0ee134e2c8d0c8e65284ede50
Version: 013ff63b649475f0ee134e2c8d0c8e65284ede50
Version: 013ff63b649475f0ee134e2c8d0c8e65284ede50
Version: 013ff63b649475f0ee134e2c8d0c8e65284ede50
Version: 013ff63b649475f0ee134e2c8d0c8e65284ede50
Version: a7accf181a4709a6e380360372150cc4a1b6b89a
Version: 3dfd727873c3e8da74a2e3907120ff052c5f0bcc
Version: 1d7dd485108d4f633b543c9c14071cc325b68ae5
Version: 5.15.209   ≤
Version: 6.1.115   ≤
Version: 6.5.11   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/record.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0441e34ce098c19185a7b52c5b8b89a8a5b26888",
              "status": "affected",
              "version": "013ff63b649475f0ee134e2c8d0c8e65284ede50",
              "versionType": "git"
            },
            {
              "lessThan": "7ab69cef49ebdfee288287d62641b24ab1445ecc",
              "status": "affected",
              "version": "013ff63b649475f0ee134e2c8d0c8e65284ede50",
              "versionType": "git"
            },
            {
              "lessThan": "ce9a619c432b9a4044fee115c5483fbed946c131",
              "status": "affected",
              "version": "013ff63b649475f0ee134e2c8d0c8e65284ede50",
              "versionType": "git"
            },
            {
              "lessThan": "2b9a0e57bfd365e2096706b19ae34dce3b4a884b",
              "status": "affected",
              "version": "013ff63b649475f0ee134e2c8d0c8e65284ede50",
              "versionType": "git"
            },
            {
              "lessThan": "20fd9f64c0050658f2031e6bd5d552c6f0c8f7e3",
              "status": "affected",
              "version": "013ff63b649475f0ee134e2c8d0c8e65284ede50",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a7accf181a4709a6e380360372150cc4a1b6b89a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3dfd727873c3e8da74a2e3907120ff052c5f0bcc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1d7dd485108d4f633b543c9c14071cc325b68ae5",
              "versionType": "git"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.209",
              "versionType": "semver"
            },
            {
              "lessThan": "6.2",
              "status": "affected",
              "version": "6.1.115",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6",
              "status": "affected",
              "version": "6.5.11",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/record.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.6"
            },
            {
              "lessThan": "6.6",
              "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",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.110",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.52",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.209",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.1.115",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.5.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: reject out-of-range evcn in mi_enum_attr()\n\nIn mi_enum_attr(), the start/end VCN validation for non-resident\nattributes is:\n\n\tif (svcn \u003e evcn + 1) goto out;\n\nWhen evcn is U64_MAX the \"evcn + 1\" expression wraps to 0 and any svcn\npasses the check. For evcn values close to U64_MAX (but not equal to it)\nthe right-hand side is still a meaningless near-wrap upper bound, so a\nmalformed on-disk attribute with svcn == 0 and evcn near U64_MAX can pass\nmi_enum_attr() unrejected.\n\nVCN (virtual cluster number) is a cluster index, so any valid evcn is\nbounded by the volume\u0027s total cluster count, which ntfs3 holds in\nsbi-\u003eused.bitmap.nbits (set up in ntfs_init_from_boot() before any caller\nof mi_enum_attr() runs). Reject evcn values that fall outside this range.\n\nHowever, an empty non-resident attribute (no allocated clusters) is\nlegitimately encoded with svcn == 0 and evcn == -1 (U64_MAX), e.g. via\nattr-\u003enres.evcn = cpu_to_le64((u64)vcn - 1) with vcn == 0. That sentinel\nmust keep passing, so exclude evcn == U64_MAX from the range check. The\nexisting \"svcn \u003e evcn + 1\" test still tolerates the sentinel (\"0 \u003e 0\" is\nfalse) and continues to require svcn == 0 for it, while the range check\nrejects every other out-of-range evcn and thereby also defuses the\n\"evcn + 1\" wraparound.\n\nsvcn does not need its own bound: once evcn \u003c nbits, \"svcn \u003e evcn + 1\"\nimplies svcn \u003c= nbits.\n\n[almaz.alexandrovich@paragon-software.com: fixed evcn check]"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The malformed field is attr-\u003enres.evcn (with svcn) in a non-resident MFT attribute on the block device. It is parsed by mount(2) \u2192 ntfs_fill_super() \u2192 ntfs_iget5() \u2192 ntfs_read_mft() \u2192 ni_enum_attr_ex() \u2192 mi_enum_attr(); no network protocol carries those VCN fields.\nAC:L - The attacker sets on-disk evcn \u2265 sbi-\u003eused.bitmap.nbits or near U64_MAX with svcn==0 so mi_enum_attr()\u0027s u64 test `svcn \u003e evcn + 1` never fails (evcn+1 wraps only at U64_MAX). A single sparse mapping pair of length evcn+1 then makes run_unpack() succeed; there is no race.\nPR:N - Crafting the NTFS image requires no account on the target. ntfs_fs_type has no FS_USERNS_MOUNT, so the CAP_SYS_ADMIN mount is the victim\u0027s action and is counted as UI:R rather than attacker privilege.\nUI:R - A victim must mount the attacker-supplied NTFS volume so ntfs_fill_super()/ntfs_read_mft() will run mi_enum_attr() on the crafted evcn; that mount is the required user action.\nS:U - Corruption stays in the host kernel\u0027s ntfs3 runs_tree and MFT record buffers; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Accepted evcn near U32_MAX is passed to run_unpack_ex() and installed as a sparse run of length ~U32_MAX. A later write hits run_add_entry(), which splits that run with wrapping CLST adds (r-\u003evcn+r-\u003elen, tail_len=r-\u003elen-Tovcn), so lookups return wrong LCNs and can read past the kvmalloc\u0027d runs array.\nI:H - The same wrapping split does `r-\u003elen += len - ((r-\u003evcn + r-\u003elen) - vcn)` and run_consolidate() joins on wrapped end points; mi_pack_runs() then writes the corrupted mapping pairs into the kmalloc\u0027d MFT record \u2014 a kernel-heap write of attacker-influenced run metadata.\nA:H - Walking off the runs array on the wrapped split, or submitting an iomap bio from a wrapped LCN in ntfs_iomap_begin() after attr_data_get_block(), oopses the kernel; attr_set_size_ex() also takes _ntfs_bad_inode() on the inconsistent vcn/evcn state."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:59:35.489Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0441e34ce098c19185a7b52c5b8b89a8a5b26888"
        },
        {
          "url": "https://git.kernel.org/stable/c/7ab69cef49ebdfee288287d62641b24ab1445ecc"
        },
        {
          "url": "https://git.kernel.org/stable/c/ce9a619c432b9a4044fee115c5483fbed946c131"
        },
        {
          "url": "https://git.kernel.org/stable/c/2b9a0e57bfd365e2096706b19ae34dce3b4a884b"
        },
        {
          "url": "https://git.kernel.org/stable/c/20fd9f64c0050658f2031e6bd5d552c6f0c8f7e3"
        }
      ],
      "title": "fs/ntfs3: reject out-of-range evcn in mi_enum_attr()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90199",
    "datePublished": "2026-09-17T16:07:17.550Z",
    "dateReserved": "2026-09-11T19:38:34.792Z",
    "dateUpdated": "2026-10-19T08:59:35.489Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.