CVE-2026-89614 (GCVE-0-2026-89614)
Vulnerability from cvelistv5
Published
2026-09-11 19:45
Modified
2026-10-19 08:49
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ntfs: bound the free-cluster bitmap scan to the volume
vol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but
ntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap.
Those are independent on-disk quantities and the mount-time check only
rejects a $Bitmap that is too small, so an image whose $Bitmap covers more
clusters than the volume has lets the scan index past the array. A run
whose LCN lies in that gap takes the allocator straight there, since the
caller passes the file's own last LCN as its locality hint. KASAN reports
a slab out-of-bounds read when a file on such a volume is extended.
Clamp the scan to what that array covers, mirroring the max_index
calculation the mount-time scan already uses, and reject a decoded LCN
at or beyond nr_clusters in the mapping pairs decoder. Conforming
volumes are unaffected.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/ntfs/lcnalloc.c",
"fs/ntfs/runlist.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "dc15a9f5307d5372aef3b64bf3ed7802f530c471",
"status": "affected",
"version": "11ccc9107dc460de28af90fac1f42404d9802735",
"versionType": "git"
},
{
"lessThan": "19cac7902a8ab748e15f98ddaafcf5f8882be21d",
"status": "affected",
"version": "11ccc9107dc460de28af90fac1f42404d9802735",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/ntfs/lcnalloc.c",
"fs/ntfs/runlist.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"lessThan": "7.1",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"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",
"versionStartIncluding": "7.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "7.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: bound the free-cluster bitmap scan to the volume\n\nvol-\u003elcn_empty_bits_per_page is sized from vol-\u003enr_clusters at mount, but\nntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap.\nThose are independent on-disk quantities and the mount-time check only\nrejects a $Bitmap that is too small, so an image whose $Bitmap covers more\nclusters than the volume has lets the scan index past the array. A run\nwhose LCN lies in that gap takes the allocator straight there, since the\ncaller passes the file\u0027s own last LCN as its locality hint. KASAN reports\na slab out-of-bounds read when a file on such a volume is extended.\n\nClamp the scan to what that array covers, mirroring the max_index\ncalculation the mount-time scan already uses, and reject a decoded LCN\nat or beyond nr_clusters in the mapping pairs decoder. Conforming\nvolumes are unaffected."
}
],
"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 nfsd/ksmbd VFS writes on an exported NTFS volume reach ntfs_file_write_iter-\u003eiomap-\u003entfs_attr_expand-\u003entfs_cluster_alloc, and reads reach ntfs_mapping_pairs_decompress, without local shell access.\nAC:L - A crafted image whose $Bitmap covers more clusters than nr_clusters, plus a file run whose LCN sits in that gap, deterministically drives the allocator to index past lcn_empty_bits_per_page and the decoder to accept out-of-volume LCNs, with no race or victim-specific layout.\nPR:N - Triggering needs only permission to cause server-side parse or extend of mounted NTFS metadata (guest/anonymous SMB, a permissive NFS export, or an unprivileged local open/write on an already-mounted volume), not init-namespace root or CAP_SYS_ADMIN at trigger time.\nUI:N - After the crafted volume is mounted and optionally exported, ordinary remote or local write/truncate/fallocate, and reads that decompress mapping pairs, trigger the bug; no extra victim mount dialog, USB insertion, or confirmation is required during the attack.\nS:U - Slab out-of-bounds access to vol-\u003elcn_empty_bits_per_page and misdirected block I/O remain in the host kernel/OS security domain and do not cross a VM, container, or IOMMU boundary to another authority.\nC:H - ntfs_cluster_alloc performs a KASAN-confirmed slab out-of-bounds read of lcn_empty_bits_per_page at an attacker-influenced page index, and decoded LCNs past nr_clusters make iomap reads disclose data beyond the NTFS volume, a kernel heap/OOB-read disclosure primitive.\nI:H - With zone_end set from the poisoned LCN, the bitmap scan calls ntfs_set_lcn_empty_bits() on out-of-range indices (heap OOB write of empty-bit counts) and iomap can write past the volume using those LCNs, a kernel memory-corruption primitive consistent with privilege escalation.\nA:H - KASAN reports a slab out-of-bounds access when a file on such a volume is extended; indexing past the kvmalloc array can oops, and the OOB write of lcn_empty_bits_per_page can panic or hang the host, so even failed exploitation denies service."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T08:49:46.853Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/dc15a9f5307d5372aef3b64bf3ed7802f530c471"
},
{
"url": "https://git.kernel.org/stable/c/19cac7902a8ab748e15f98ddaafcf5f8882be21d"
}
],
"title": "ntfs: bound the free-cluster bitmap scan to the volume",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-89614",
"datePublished": "2026-09-11T19:45:14.747Z",
"dateReserved": "2026-09-11T19:38:34.735Z",
"dateUpdated": "2026-10-19T08:49:46.853Z",
"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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