FKIE_CVE-2026-72191
Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-23 13:16
Severity
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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"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": "8e4ba5a38c155bb3c1c11e63cd285b178cdb099e",
"status": "affected",
"version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
"versionType": "git"
},
{
"lessThan": "4c2f648139a0a86f4486170f72e24fedd4fae74e",
"status": "affected",
"version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
"versionType": "git"
},
{
"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": "5.15.*",
"status": "unaffected",
"version": "5.15.217",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.184",
"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"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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."
}
],
"id": "CVE-2026-72191",
"lastModified": "2026-08-23T13:16:41.680",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T06:21:37.537",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1758a564b6ebe7f4a82f23c9851d1cae15549457"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4c2f648139a0a86f4486170f72e24fedd4fae74e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7bf74e6baf810fe325f111996496c678fc6e244f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/8e4ba5a38c155bb3c1c11e63cd285b178cdb099e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b232eb5c9fe11ec2368e9b565db69c724c35fbd2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f1df9d771df47aa40de6d70949c28720ae1e430d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f3624cc069195001c88df7a291af215f2133ff2c"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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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.
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