CVE-2026-90117 (GCVE-0-2026-90117)
Vulnerability from cvelistv5
Published
2026-09-17 16:06
Modified
2026-10-19 08:58
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ntfs: validate usa_ofs before preserving the update sequence number
When ntfs_mft_record_alloc() reuses a free mft record it reads the old
update sequence number straight from the on-disk record:
usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs));
Here m points into the raw $MFT page-cache folio, which still holds
unvalidated, MST-protected bytes: the folio is read by a plain
iomap_read_folio() and neither post_read_mst_fixup() nor
ntfs_mft_record_check() has run on it (both work on private copies).
m->usa_ofs is therefore an untrusted u16, and a corrupted record can put
it past the end of the record so the two-byte read lands outside the
folio. Reading such a record while creating a file gives, under KASAN:
BUG: KASAN: use-after-free in ntfs_mft_record_alloc+...
Read of size 2 at addr ...
ntfs_mft_record_alloc -> __ntfs_create -> ntfs_create -> path_openat
Only preserve the old update sequence number when usa_ofs is even and in
range, mirroring the check ntfs_mft_record_check() already applies;
otherwise leave usn zero, which the existing restore below skips.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/ntfs/mft.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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"status": "affected",
"version": "495e90fa334828d4119061e2726af51d0a0fb4ed",
"versionType": "git"
},
{
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"status": "affected",
"version": "495e90fa334828d4119061e2726af51d0a0fb4ed",
"versionType": "git"
}
]
},
{
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"product": "Linux",
"programFiles": [
"fs/ntfs/mft.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
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"status": "unaffected",
"version": "0",
"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": "7.2.6",
"versionStartIncluding": "7.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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}
],
"negate": false,
"operator": "OR"
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: validate usa_ofs before preserving the update sequence number\n\nWhen ntfs_mft_record_alloc() reuses a free mft record it reads the old\nupdate sequence number straight from the on-disk record:\n\n usn = *(__le16 *)((u8 *)m + le16_to_cpu(m-\u003eusa_ofs));\n\nHere m points into the raw $MFT page-cache folio, which still holds\nunvalidated, MST-protected bytes: the folio is read by a plain\niomap_read_folio() and neither post_read_mst_fixup() nor\nntfs_mft_record_check() has run on it (both work on private copies).\nm-\u003eusa_ofs is therefore an untrusted u16, and a corrupted record can put\nit past the end of the record so the two-byte read lands outside the\nfolio. Reading such a record while creating a file gives, under KASAN:\n\n BUG: KASAN: use-after-free in ntfs_mft_record_alloc+...\n Read of size 2 at addr ...\n ntfs_mft_record_alloc -\u003e __ntfs_create -\u003e ntfs_create -\u003e path_openat\n\nOnly preserve the old update sequence number when usa_ofs is even and in\nrange, mirroring the check ntfs_mft_record_check() already applies;\notherwise leave usn zero, which the existing restore below skips."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T08:58:15.750Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/ea5a3c30710710c1dc5e483d3313309ec2e868f7"
},
{
"url": "https://git.kernel.org/stable/c/81684340963da2e898eabb8c1e274433d9375bc6"
}
],
"title": "ntfs: validate usa_ofs before preserving the update sequence number",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
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"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-90117",
"datePublished": "2026-09-17T16:06:22.705Z",
"dateReserved": "2026-09-11T19:38:34.787Z",
"dateUpdated": "2026-10-19T08:58:15.750Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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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.
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