CVE-2025-40268 (GCVE-0-2025-40268)
Vulnerability from cvelistv5 – Published: 2025-12-06 21:50 – Updated: 2026-05-11 21:46
VLAI
EPSS
VEX
Title
cifs: client: fix memory leak in smb3_fs_context_parse_param
Summary
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.
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:1438
Severity
No CVSS data available.
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 868fc62811d3fabcf5685e14f36377a855d5412d
(git)
Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 48c17341577e25a22feb13d694374b61d974edbc (git) Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 4515743cc7a42e1d67468402a6420c195532a6fa (git) Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6 (git) |
guessed | |
| Linux | Linux |
Affected:
5.11
Unaffected: 0 , < 5.11 (semver) Unaffected: 6.6.117 , ≤ 6.6.* (semver) Unaffected: 6.12.59 , ≤ 6.12.* (semver) Unaffected: 6.17.9 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
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"product": "Linux",
"programFiles": [
"fs/smb/client/fs_context.c"
],
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"status": "affected",
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],
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{
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{
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"version": "6.12.59",
"versionType": "semver"
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"version": "6.17.9",
"versionType": "semver"
},
{
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"version": "6.18",
"versionType": "original_commit_for_fix"
}
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}
],
"cpeApplicability": [
{
"nodes": [
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"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "5.11",
"vulnerable": true
},
{
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"versionEndExcluding": "6.12.59",
"versionStartIncluding": "5.11",
"vulnerable": true
},
{
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},
{
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}
],
"negate": false,
"operator": "OR"
}
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}
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"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-\u003esource for the second fsconfig, not the first.\nRegarding fc-\u003esource, 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"
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T21:46:04.012Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/868fc62811d3fabcf5685e14f36377a855d5412d"
},
{
"url": "https://git.kernel.org/stable/c/48c17341577e25a22feb13d694374b61d974edbc"
},
{
"url": "https://git.kernel.org/stable/c/4515743cc7a42e1d67468402a6420c195532a6fa"
},
{
"url": "https://git.kernel.org/stable/c/e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6"
}
],
"title": "cifs: client: fix memory leak in smb3_fs_context_parse_param",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-40268",
"datePublished": "2025-12-06T21:50:48.917Z",
"dateReserved": "2025-04-16T07:20:57.183Z",
"dateUpdated": "2026-05-11T21:46:04.012Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2025-40268",
"date": "2026-09-28",
"epss": "0.00187",
"percentile": "0.0746"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"versionType": "git"
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}
]
},
{
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.11"
},
{
"lessThan": "5.11",
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"version": "0",
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{
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"versionType": "semver"
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{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.59",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.17.*",
"status": "unaffected",
"version": "6.17.9",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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-\u003esource for the second fsconfig, not the first.\nRegarding fc-\u003esource, 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"
}
],
"id": "CVE-2025-40268",
"lastModified": "2026-06-17T09:21:33.833",
"metrics": {},
"published": "2025-12-06T22:15:54.327",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"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"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Deferred"
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-06-30T10:31:48+00:00",
"cve": "CVE-2025-40268",
"id": "CVE-2025-40268",
"initial_release_date": "2025-12-06T00:00:00+00:00",
"product_status:known_affected": "232",
"product_status:known_not_affected": "42",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: cifs: client: fix memory leak in smb3_fs_context_parse_param",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-40268.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-09-11T01:54:19Z",
"cve": "CVE-2025-40268",
"id": "CVE-2025-40268",
"initial_release_date": "2025-12-08T00:23:26Z",
"product_status:first_fixed": "2",
"product_status:known_affected": "610",
"product_status:known_not_affected": "260",
"product_status:recommended": "289",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2025-40268",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-40268.json",
"version": "42"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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