CVE-2026-98124
In the Linux kernel, the following vulnerability has been resolved:
smb/client: invalidate fscache for fallocate range operations
smb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and smb3_collapse_range() modify file contents through server-side range operations. These operations discard the affected page cache, but leave the FS-Cache cookie valid, so a later read may return data cached before the range operation.
Fix this by invalidating FS-Cache after outstanding I/O has completed and before modifying the file on the server.
Run the following as root on a CIFS mount with fsc enabled and an active CacheFiles backend:
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Before this change, the readback differs from /tmp/expected:
After this change, it matches:
Detalles técnicos trazas, registros y código del informe original
bash -c '
MNT=/mnt/cifs
FILE="$MNT/repro"
# Generate four 1 MiB random blocks: [A][B][C][D].
dd if=/dev/urandom of=/tmp/src bs=1M count=4 status=none
# Expected contents after zeroing B: [A][zero][C][D].
cp /tmp/src /tmp/expected
dd if=/dev/zero of=/tmp/expected bs=1M seek=1 count=1 \
conv=notrunc status=none
cp /tmp/src "$FILE"
# Populate FS-Cache, then discard the page cache.
sync
echo 1 > /proc/sys/vm/drop_caches
cat "$FILE" > /dev/null
sync
echo 1 > /proc/sys/vm/drop_caches
fallocate --zero-range -o 1M -l 1M "$FILE"
if cmp -s /tmp/expected "$FILE"; then
echo "readback: OK"
else
echo "readback: STALE DATA"
fi
'
readback: STALE DATA
readback: OKCVSS
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: 0.16%
- Percentil entre todas las CVEs puntuadas: 4
- 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-2026-98124",
"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": "31742c5a331766bc7df6b0d525df00c6cd20d5a6",
"lessThan": "93c6e5a8d7c5071d586c1411596d5db5faad22b2",
"versionType": "git"
},
{
"status": "affected",
"version": "31742c5a331766bc7df6b0d525df00c6cd20d5a6",
"lessThan": "448ba0ae65ca61064183564d2983c9aa59bd6ba7",
"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": "3.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.17",
"versionType": "semver"
},
{
"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": "2026-09-25T11:17:43.720",
"references": [
{
"url": "https://git.kernel.org/stable/c/448ba0ae65ca61064183564d2983c9aa59bd6ba7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/93c6e5a8d7c5071d586c1411596d5db5faad22b2",
"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: invalidate fscache for fallocate range operations\n\nsmb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and\nsmb3_collapse_range() modify file contents through server-side range\noperations. These operations discard the affected page cache, but leave\nthe FS-Cache cookie valid, so a later read may return data cached before\nthe range operation.\n\nFix this by invalidating FS-Cache after outstanding I/O has completed\nand before modifying the file on the server.\n\nRun the following as root on a CIFS mount with fsc enabled and an active\nCacheFiles backend:\n\n bash -c '\n MNT=/mnt/cifs\n FILE=\"$MNT/repro\"\n\n # Generate four 1 MiB random blocks: [A][B][C][D].\n dd if=/dev/urandom of=/tmp/src bs=1M count=4 status=none\n\n # Expected contents after zeroing B: [A][zero][C][D].\n cp /tmp/src /tmp/expected\n dd if=/dev/zero of=/tmp/expected bs=1M seek=1 count=1 \\\n conv=notrunc status=none\n cp /tmp/src \"$FILE\"\n\n # Populate FS-Cache, then discard the page cache.\n sync\n echo 1 > /proc/sys/vm/drop_caches\n cat \"$FILE\" > /dev/null\n sync\n echo 1 > /proc/sys/vm/drop_caches\n\n fallocate --zero-range -o 1M -l 1M \"$FILE\"\n\n if cmp -s /tmp/expected \"$FILE\"; then\n echo \"readback: OK\"\n else\n echo \"readback: STALE DATA\"\n fi\n '\n\nBefore this change, the readback differs from /tmp/expected:\n\n readback: STALE DATA\n\nAfter this change, it matches:\n\n readback: OK"
}
],
"lastModified": "2026-09-30T14:10:59.253",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}