Vulnerability-Lookup

GHSA-RW89-WM92-GVRJ

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

ntfs3: validate split-point offset in indx_insert_into_buffer

indx_insert_into_buffer() computes

used = used1 - to_copy - sp_size;
memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));

where sp and sp_size come from hdr_find_split(). hdr_find_split() walks entries by le16_to_cpu(e->size) without validating that each step stays within hdr->used or that the size field is at least sizeof(struct NTFS_DE). index_hdr_check(), the on-load gatekeeper, only validates header-level fields (used, total, de_off) and does not walk per-entry sizes.

A crafted NTFS image whose leaf INDEX_HDR reports used == total but contains one interior NTFS_DE with size = 0xFFF0 therefore passes validation, descends to indx_insert_into_buffer() through the ntfs_create() -> indx_insert_entry() path, and makes hdr_find_split() return an sp whose sp_size (0xFFF0) greatly exceeds the remaining bytes in the buffer. The u32 subtraction underflows and the memmove count becomes a near-4-GiB value, producing an out-of-bounds kernel write that corrupts adjacent allocations and panics the kernel.

Reproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a single 'touch' inside the mounted directory; crash site resolves to fs/ntfs3/index.c at the memmove. Trigger requires only local mount of an attacker-supplied filesystem image (USB, loopback, or removable media auto-mount).

Reject the split whenever the chosen sp plus its declared size already extends past hdr1->used. This is the minimal fix; it preserves the existing hdr_find_split() contract and relies on the same out: cleanup path as the pre-existing error returns.

A prior OOB read in the very same indx_insert_into_buffer() memmove was fixed in commit b8c44949044e ("fs/ntfs3: Fix OOB read in indx_insert_into_buffer") by tightening hdr_find_e(), but that fix does not cover the split-point size field path addressed here: sp is returned by hdr_find_split(), not hdr_find_e(), and the underflow is driven by sp->size rather than hdr->used exceeding hdr->total.

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-2026-72191"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:21:37Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: validate split-point offset in indx_insert_into_buffer\n\nindx_insert_into_buffer() computes\n\n    used = used1 - to_copy - sp_size;\n    memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1-\u003ede_off));\n\nwhere sp and sp_size come from hdr_find_split().  hdr_find_split()\nwalks entries by le16_to_cpu(e-\u003esize) without validating that each\nstep stays within hdr-\u003eused or that the size field is at least\nsizeof(struct NTFS_DE).  index_hdr_check(), the on-load gatekeeper,\nonly validates header-level fields (used, total, de_off) and does\nnot walk per-entry sizes.\n\nA crafted NTFS image whose leaf INDEX_HDR reports used == total but\ncontains one interior NTFS_DE with size = 0xFFF0 therefore passes\nvalidation, descends to indx_insert_into_buffer() through the\nntfs_create() -\u003e indx_insert_entry() path, and makes hdr_find_split()\nreturn an sp whose sp_size (0xFFF0) greatly exceeds the remaining\nbytes in the buffer.  The u32 subtraction underflows and the memmove\ncount becomes a near-4-GiB value, producing an out-of-bounds kernel\nwrite that corrupts adjacent allocations and panics the kernel.\n\nReproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a\nsingle \u0027touch\u0027 inside the mounted directory; crash site resolves to\nfs/ntfs3/index.c at the memmove.  Trigger requires only local mount\nof an attacker-supplied filesystem image (USB, loopback, or removable\nmedia auto-mount).\n\nReject the split whenever the chosen sp plus its declared size\nalready extends past hdr1-\u003eused.  This is the minimal fix; it\npreserves the existing hdr_find_split() contract and relies on the\nsame out: cleanup path as the pre-existing error returns.\n\nA prior OOB read in the very same indx_insert_into_buffer() memmove\nwas fixed in commit b8c44949044e (\"fs/ntfs3: Fix OOB read in\nindx_insert_into_buffer\") by tightening hdr_find_e(), but that fix\ndoes not cover the split-point size field path addressed here: sp is\nreturned by hdr_find_split(), not hdr_find_e(), and the underflow is\ndriven by sp-\u003esize rather than hdr-\u003eused exceeding hdr-\u003etotal.",
  "id": "GHSA-rw89-wm92-gvrj",
  "modified": "2026-08-17T06:33:15Z",
  "published": "2026-08-15T06:32:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72191"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1758a564b6ebe7f4a82f23c9851d1cae15549457"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7bf74e6baf810fe325f111996496c678fc6e244f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b232eb5c9fe11ec2368e9b565db69c724c35fbd2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f1df9d771df47aa40de6d70949c28720ae1e430d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f3624cc069195001c88df7a291af215f2133ff2c"
    }
  ],
  "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-2026-72191 (GCVE-0-2026-72191)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:53 – Updated: 2026-08-17 05:41

Title

ntfs3: validate split-point offset in indx_insert_into_buffer

Summary

In the Linux kernel, the following vulnerability has been resolved: ntfs3: validate split-point offset in indx_insert_into_buffer indx_insert_into_buffer() computes used = used1 - to_copy - sp_size; memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off)); where sp and sp_size come from hdr_find_split(). hdr_find_split() walks entries by le16_to_cpu(e->size) without validating that each step stays within hdr->used or that the size field is at least sizeof(struct NTFS_DE). index_hdr_check(), the on-load gatekeeper, only validates header-level fields (used, total, de_off) and does not walk per-entry sizes. A crafted NTFS image whose leaf INDEX_HDR reports used == total but contains one interior NTFS_DE with size = 0xFFF0 therefore passes validation, descends to indx_insert_into_buffer() through the ntfs_create() -> indx_insert_entry() path, and makes hdr_find_split() return an sp whose sp_size (0xFFF0) greatly exceeds the remaining bytes in the buffer. The u32 subtraction underflows and the memmove count becomes a near-4-GiB value, producing an out-of-bounds kernel write that corrupts adjacent allocations and panics the kernel. Reproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a single 'touch' inside the mounted directory; crash site resolves to fs/ntfs3/index.c at the memmove. Trigger requires only local mount of an attacker-supplied filesystem image (USB, loopback, or removable media auto-mount). Reject the split whenever the chosen sp plus its declared size already extends past hdr1->used. This is the minimal fix; it preserves the existing hdr_find_split() contract and relies on the same out: cleanup path as the pre-existing error returns. A prior OOB read in the very same indx_insert_into_buffer() memmove was fixed in commit b8c44949044e ("fs/ntfs3: Fix OOB read in indx_insert_into_buffer") by tightening hdr_find_e(), but that fix does not cover the split-point size field path addressed here: sp is returned by hdr_find_split(), not hdr_find_e(), and the underflow is driven by sp->size rather than hdr->used exceeding hdr->total.

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 mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/b232eb5c9fe11ec23…
https://git.kernel.org/stable/c/7bf74e6baf810fe32…
https://git.kernel.org/stable/c/f3624cc069195001c…
https://git.kernel.org/stable/c/1758a564b6ebe7f4a…
https://git.kernel.org/stable/c/f1df9d771df47aa40…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 82cae269cfa953032fbb8980a7d554d60fb00b17 , < b232eb5c9fe11ec2368e9b565db69c724c35fbd2 (git) Affected: 82cae269cfa953032fbb8980a7d554d60fb00b17 , < 7bf74e6baf810fe325f111996496c678fc6e244f (git) Affected: 82cae269cfa953032fbb8980a7d554d60fb00b17 , < f3624cc069195001c88df7a291af215f2133ff2c (git) Affected: 82cae269cfa953032fbb8980a7d554d60fb00b17 , < 1758a564b6ebe7f4a82f23c9851d1cae15549457 (git) Affected: 82cae269cfa953032fbb8980a7d554d60fb00b17 , < f1df9d771df47aa40de6d70949c28720ae1e430d (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/index.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b232eb5c9fe11ec2368e9b565db69c724c35fbd2",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "7bf74e6baf810fe325f111996496c678fc6e244f",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "f3624cc069195001c88df7a291af215f2133ff2c",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "1758a564b6ebe7f4a82f23c9851d1cae15549457",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            },
            {
              "lessThan": "f1df9d771df47aa40de6d70949c28720ae1e430d",
              "status": "affected",
              "version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/index.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": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: validate split-point offset in indx_insert_into_buffer\n\nindx_insert_into_buffer() computes\n\n    used = used1 - to_copy - sp_size;\n    memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1-\u003ede_off));\n\nwhere sp and sp_size come from hdr_find_split().  hdr_find_split()\nwalks entries by le16_to_cpu(e-\u003esize) without validating that each\nstep stays within hdr-\u003eused or that the size field is at least\nsizeof(struct NTFS_DE).  index_hdr_check(), the on-load gatekeeper,\nonly validates header-level fields (used, total, de_off) and does\nnot walk per-entry sizes.\n\nA crafted NTFS image whose leaf INDEX_HDR reports used == total but\ncontains one interior NTFS_DE with size = 0xFFF0 therefore passes\nvalidation, descends to indx_insert_into_buffer() through the\nntfs_create() -\u003e indx_insert_entry() path, and makes hdr_find_split()\nreturn an sp whose sp_size (0xFFF0) greatly exceeds the remaining\nbytes in the buffer.  The u32 subtraction underflows and the memmove\ncount becomes a near-4-GiB value, producing an out-of-bounds kernel\nwrite that corrupts adjacent allocations and panics the kernel.\n\nReproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a\nsingle \u0027touch\u0027 inside the mounted directory; crash site resolves to\nfs/ntfs3/index.c at the memmove.  Trigger requires only local mount\nof an attacker-supplied filesystem image (USB, loopback, or removable\nmedia auto-mount).\n\nReject the split whenever the chosen sp plus its declared size\nalready extends past hdr1-\u003eused.  This is the minimal fix; it\npreserves the existing hdr_find_split() contract and relies on the\nsame out: cleanup path as the pre-existing error returns.\n\nA prior OOB read in the very same indx_insert_into_buffer() memmove\nwas fixed in commit b8c44949044e (\"fs/ntfs3: Fix OOB read in\nindx_insert_into_buffer\") by tightening hdr_find_e(), but that fix\ndoes not cover the split-point size field path addressed here: sp is\nreturned by hdr_find_split(), not hdr_find_e(), and the underflow is\ndriven by sp-\u003esize rather than hdr-\u003eused exceeding hdr-\u003etotal."
        }
      ],
      "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 - Remote SMB CREATE via ksmbd vfs_create on an ntfs3-exported share reaches ntfs_create_inode\u2192indx_insert_entry\u2192indx_insert_into_buffer; the same memmove path is also reachable locally via open(O_CREAT)/touch on a mounted crafted image.\nAC:L - The attacker fully controls the on-disk leaf INDEX_HDR and NTFS_DE size (e.g. 0xFFF0); once the buffer is full and a create forces a split, hdr_find_split() deterministically selects the bad entry and the u32 underflow yields a reliable near-4GiB OOB memmove with no race.\nPR:N - Exploitation requires only a crafted NTFS image and a create in the malicious directory\u2014no root on the target\u2014via udisks2/systemd automount of attacker USB media, or a remote ksmbd client with guest/anonymous write access to an already-mounted ntfs3 export.\nUI:N - After the crafted volume is mounted (automounter or admin), a single attacker-initiated touch/create or remote SMB CREATE in the prepared full directory triggers the split and OOB memmove without any further victim clicks, prompts, or confirmation.\nS:U - The OOB memmove corrupts kernel heap memory within the same host OS security domain as ntfs3; it can enable local privilege escalation but does not cross a VM/hypervisor, IOMMU, or container sandbox boundary.\nC:H - The underflowed memmove length reads far beyond the kmalloc\u0027d index buffer from attacker-controlled on-disk bytes, giving a large out-of-bounds kernel heap read and disclosure/corruption primitive in addition to the write side.\nI:H - The same memmove performs a massive out-of-bounds kernel heap write of adjacent slab objects with attacker-influenced source data, enabling arbitrary memory corruption and potential control-flow hijack beyond a simple denial of service.\nA:H - Reproduced on 7.0.0-rc7 with KASAN: the oversized memmove corrupts adjacent allocations and panics the kernel at fs/ntfs3/index.c; even failed exploitation attempts typically cause oops or hard lockup from the unbounded copy."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:41:18.532Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b232eb5c9fe11ec2368e9b565db69c724c35fbd2"
        },
        {
          "url": "https://git.kernel.org/stable/c/7bf74e6baf810fe325f111996496c678fc6e244f"
        },
        {
          "url": "https://git.kernel.org/stable/c/f3624cc069195001c88df7a291af215f2133ff2c"
        },
        {
          "url": "https://git.kernel.org/stable/c/1758a564b6ebe7f4a82f23c9851d1cae15549457"
        },
        {
          "url": "https://git.kernel.org/stable/c/f1df9d771df47aa40de6d70949c28720ae1e430d"
        }
      ],
      "title": "ntfs3: validate split-point offset in indx_insert_into_buffer",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72191",
    "datePublished": "2026-08-15T05:53:51.893Z",
    "dateReserved": "2026-08-09T03:40:39.911Z",
    "dateUpdated": "2026-08-17T05:41:18.532Z",
    "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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
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.

Action not permitted

GHSA-RW89-WM92-GVRJ

CVE-2026-72191 (GCVE-0-2026-72191)

Tags

Sightings

Nomenclature