CVE-2025-40268
In the Linux kernel, the following vulnerability has been resolved:
cifs: client: fix memory leak in smb3_fs_context_parse_param
The user calls fsconfig twice, but when the program exits, free() only frees ctx->source for the second fsconfig, not the first. Regarding fc->source, there is no code in the fs context related to its memory reclamation.
To fix this memory leak, release the source memory corresponding to ctx or fc before each parsing.
Detalles técnicos trazas, registros y código del informe original
syzbot reported:
BUG: memory leak
unreferenced object 0xffff888128afa360 (size 96):
backtrace (crc 79c9c7ba):
kstrdup+0x3c/0x80 mm/util.c:84
smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444
BUG: memory leak
unreferenced object 0xffff888112c7d900 (size 96):
backtrace (crc 79c9c7ba):
smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629
smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438CVSS
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: 0.19%
- Percentil entre todas las CVEs puntuadas: 8
- 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
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-40268",
"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": "af1a3d2ba9543e99d78914d8fb88b61d0531d9a1",
"lessThan": "868fc62811d3fabcf5685e14f36377a855d5412d",
"versionType": "git"
},
{
"status": "affected",
"version": "af1a3d2ba9543e99d78914d8fb88b61d0531d9a1",
"lessThan": "48c17341577e25a22feb13d694374b61d974edbc",
"versionType": "git"
},
{
"status": "affected",
"version": "af1a3d2ba9543e99d78914d8fb88b61d0531d9a1",
"lessThan": "4515743cc7a42e1d67468402a6420c195532a6fa",
"versionType": "git"
},
{
"status": "affected",
"version": "af1a3d2ba9543e99d78914d8fb88b61d0531d9a1",
"lessThan": "e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6",
"versionType": "git"
}
],
"programFiles": [
"fs/smb/client/fs_context.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.117",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.59",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.17.9",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/fs_context.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-06T22:15:54.327",
"references": [
{
"url": "https://git.kernel.org/stable/c/4515743cc7a42e1d67468402a6420c195532a6fa",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/48c17341577e25a22feb13d694374b61d974edbc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/868fc62811d3fabcf5685e14f36377a855d5412d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: client: fix memory leak in smb3_fs_context_parse_param\n\nThe user calls fsconfig twice, but when the program exits, free() only\nfrees ctx->source for the second fsconfig, not the first.\nRegarding fc->source, there is no code in the fs context related to its\nmemory reclamation.\n\nTo fix this memory leak, release the source memory corresponding to ctx\nor fc before each parsing.\n\nsyzbot reported:\nBUG: memory leak\nunreferenced object 0xffff888128afa360 (size 96):\n backtrace (crc 79c9c7ba):\n kstrdup+0x3c/0x80 mm/util.c:84\n smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444\n\nBUG: memory leak\nunreferenced object 0xffff888112c7d900 (size 96):\n backtrace (crc 79c9c7ba):\n smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629\n smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438"
}
],
"lastModified": "2026-06-17T09:21:33.833",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}