CVE-2026-98126
In the Linux kernel, the following vulnerability has been resolved:
smb/client: validate new EOF for zero range
When FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE, smb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing the file to grow beyond the caller's file-size limit.
Fix this by calling inode_newsize_ok() before sending the zero-range request when the operation would extend EOF.
Reproducer, using a file on a CIFS mount:
trap "" SIGXFSZ ulimit -f 3072
truncate -s 2M "$FILE" fallocate --zero-range -o 0 -l 4M "$FILE" echo "fallocate rc=$?" stat -c "file size=%s" "$FILE" '
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Before this change, the operation succeeds despite the 3 MiB limit:
After this change, fallocate fails and leaves the file at 2 MiB.
Detalles técnicos trazas, registros y código del informe original
bash -c ' FILE=/mnt/cifs/repro fallocate rc=0 file size=4194304
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: 0.17%
- Percentil entre todas las CVEs puntuadas: 6
- Fecha de la puntuación: 5/10/2026
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
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98126",
"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": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
"lessThan": "3673f057b64abfa957e8ae84448db69369a5091a",
"versionType": "git"
},
{
"status": "affected",
"version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
"lessThan": "06a4f9049cb6dc319bceec2dc813ba89add8b828",
"versionType": "git"
},
{
"status": "affected",
"version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
"lessThan": "f320ca20c273a26cd779bdb2b2e4b076a95c76f6",
"versionType": "git"
},
{
"status": "affected",
"version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
"lessThan": "88972e35750792e717af287dc71f42a03b5cbce4",
"versionType": "git"
}
],
"programFiles": [
"fs/smb/client/smb2ops.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/smb2ops.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-25T11:17:43.940",
"references": [
{
"url": "https://git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Undergoing Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: validate new EOF for zero range\n\nWhen FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE,\nsmb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing\nthe file to grow beyond the caller's file-size limit.\n\nFix this by calling inode_newsize_ok() before sending the zero-range\nrequest when the operation would extend EOF.\n\nReproducer, using a file on a CIFS mount:\n\n\tbash -c '\n\t FILE=/mnt/cifs/repro\n\n\t trap \"\" SIGXFSZ\n\t ulimit -f 3072\n\n\t truncate -s 2M \"$FILE\"\n\t fallocate --zero-range -o 0 -l 4M \"$FILE\"\n\t echo \"fallocate rc=$?\"\n\t stat -c \"file size=%s\" \"$FILE\"\n\t'\n\nBefore this change, the operation succeeds despite the 3 MiB limit:\n\n\tfallocate rc=0\n\tfile size=4194304\n\nAfter this change, fallocate fails and leaves the file at 2 MiB."
}
],
"lastModified": "2026-09-30T14:10:59.253",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}