CVE-2026-90200
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: fix integer overflow in MFT cluster validation
In ntfs_init_from_boot(), the boot sector's MFT cluster numbers are validated against the volume size with:
mlcn and mlcn2 are u64 fields read directly from the boot sector. sct_per_clst is bounded above by 4096 (true_sectors_per_clst() plus the is_power_of_2() check below it), but the multiplication is done in u64 and wraps when mlcn (or mlcn2) is large enough -- e.g. mlcn near 2^62 with sct_per_clst == 4 wraps to 0, which compares below any non-zero 'sectors', so the check is bypassed and the malformed record is accepted.
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The accepted mlcn is then used unchanged in
In practice the resulting reads fail at the block layer (sb_bread() returns NULL via grow_buffers()'s check_mul_overflow() guard), so today this manifests as mount failing in odd places rather than as something more dangerous, but the validation step is still wrong and there is no reason for callers to rely on the block layer to catch a value that should never have been accepted in the first place.
Use check_mul_overflow() to compute the two sector positions and fail the mount if either multiplication wraps; this preserves the existing semantics (mlcn * sct_per_clst >= sectors) instead of switching to division (mlcn >= sectors / sct_per_clst), which would tighten the check at edge cases where 'sectors' is not a multiple of sct_per_clst. The check_*_overflow() style is the one ntfs3 already uses for similar on-disk arithmetic in fs/ntfs3/run.c.
Detalles técnicos trazas, registros y código del informe original
if (mlcn * sct_per_clst >= sectors || mlcn2 * sct_per_clst >= sectors) goto out; sbi->mft.lbo = mlcn << cluster_bits;
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.22%
- Percentil entre todas las CVEs puntuadas: 11
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/169383d8914b8fe03464a83540b5b6de3e7831af
- https://git.kernel.org/stable/c/805cc5554b13d045dce9b03c13eaf015418739fd
- https://git.kernel.org/stable/c/c510c63873103a5da6a498fe537bdb5d6f8d03a2
- https://git.kernel.org/stable/c/dc6d85de7e2656e56e10ff5ba514f2583a4f612b
- https://git.kernel.org/stable/c/f77a8d9fdf58e298b36564a44c27fadc617bdd28
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-90200",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "82cae269cfa953032fbb8980a7d554d60fb00b17",
"lessThan": "f77a8d9fdf58e298b36564a44c27fadc617bdd28",
"versionType": "git"
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{
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{
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{
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"lessThan": "c510c63873103a5da6a498fe537bdb5d6f8d03a2",
"versionType": "git"
}
],
"programFiles": [
"fs/ntfs3/super.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/ntfs3/super.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-17T17:17:14.930",
"references": [
{
"url": "https://git.kernel.org/stable/c/169383d8914b8fe03464a83540b5b6de3e7831af",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/805cc5554b13d045dce9b03c13eaf015418739fd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/c510c63873103a5da6a498fe537bdb5d6f8d03a2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/dc6d85de7e2656e56e10ff5ba514f2583a4f612b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f77a8d9fdf58e298b36564a44c27fadc617bdd28",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: fix integer overflow in MFT cluster validation\n\nIn ntfs_init_from_boot(), the boot sector's MFT cluster numbers are\nvalidated against the volume size with:\n\n\tif (mlcn * sct_per_clst >= sectors ||\n\t mlcn2 * sct_per_clst >= sectors)\n\t\tgoto out;\n\nmlcn and mlcn2 are u64 fields read directly from the boot sector.\nsct_per_clst is bounded above by 4096 (true_sectors_per_clst() plus\nthe is_power_of_2() check below it), but the multiplication is done\nin u64 and wraps when mlcn (or mlcn2) is large enough -- e.g. mlcn\nnear 2^62 with sct_per_clst == 4 wraps to 0, which compares below\nany non-zero 'sectors', so the check is bypassed and the malformed\nrecord is accepted.\n\nThe accepted mlcn is then used unchanged in\n\n\tsbi->mft.lbo = mlcn << cluster_bits;\n\nIn practice the resulting reads fail at the block layer (sb_bread()\nreturns NULL via grow_buffers()'s check_mul_overflow() guard), so\ntoday this manifests as mount failing in odd places rather than as\nsomething more dangerous, but the validation step is still wrong\nand there is no reason for callers to rely on the block layer to\ncatch a value that should never have been accepted in the first\nplace.\n\nUse check_mul_overflow() to compute the two sector positions and\nfail the mount if either multiplication wraps; this preserves the\nexisting semantics (mlcn * sct_per_clst >= sectors) instead of\nswitching to division (mlcn >= sectors / sct_per_clst), which\nwould tighten the check at edge cases where 'sectors' is not a\nmultiple of sct_per_clst. The check_*_overflow() style is the\none ntfs3 already uses for similar on-disk arithmetic in\nfs/ntfs3/run.c."
}
],
"lastModified": "2026-09-17T17:17:14.930",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}