ksmbd: fix potencial OOB in get_file_all_info() for compound requests
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix potencial OOB in get_file_all_info() for compound requests When a compound request consists of QUERY_DIRECTORY + QUERY_INFO (FILE_ALL_INFORMATION) and the first command consumes nearly the entire max_trans_size, get_file_all_info() would blindly call smbConvertToUTF16() with PATH_MAX, causing out-of-bounds write beyond the response buffer. In get_file_all_info(), there was a missing validation check for the client-provided OutputBufferLength before copying the filename into FileName field of the smb2_file_all_info structure. If the filename length exceeds the available buffer space, it could lead to potential buffer overflows or memory corruption during smbConvertToUTF16 conversion. This calculating the actual free buffer size using smb2_calc_max_out_buf_len() and returning -EINVAL if the buffer is insufficient and updating smbConvertToUTF16 to use the actual filename length (clamped by PATH_MAX) to ensure a safe copy operation.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 5.15.203, 6.1.168, 6.12.80, 6.18.21, 6.19.11, 6.6.131
- CVEs
- CVE-2026-31433
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 21:38 UTC · Revision 1
Source evidence
ksmbd: fix potencial OOB in get_file_all_info() for compound requests
core-osv · Original sourcePublished 22 Apr 2026, 08:15 UTC
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix potencial OOB in get_file_all_info() for compound requests When a compound request consists of QUERY_DIRECTORY + QUERY_INFO (FILE_ALL_INFORMATION) and the first command consumes nearly the entire max_trans_size, get_file_all_info() would blindly call smbConvertToUTF16() with PATH_MAX, causing out-of-bounds write beyond the response buffer. In get_file_all_info(), there was a missing validation check for the client-provided OutputBufferLength before copying the filename into FileName field of the smb2_file_all_info structure. If the filename length exceeds the available buffer space, it could lead to potential buffer overflows or memory corruption during smbConvertToUTF16 conversion. This calculating the actual free buffer size using smb2_calc_max_out_buf_len() and returning -EINVAL if the buffer is insufficient and updating smbConvertToUTF16 to use the actual filename length (clamped by PATH_MAX) to ensure a safe copy operation.
osv:CVE-2026-31433
Kernel
Fixed versions: 5.15.203, 6.1.168, 6.6.131, 6.12.80, 6.18.21, 6.19.11
Complete source record
{
"id": "f8c3e555ee561c9d2fb5fce74a04aedf8da947f1b39cc2f2d189e5235b7df28d",
"url": "https://osv.dev/vulnerability/CVE-2026-31433",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "ksmbd: fix potencial OOB in get_file_all_info() for compound requests",
"summary": "In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix potencial OOB in get_file_all_info() for compound requests When a compound request consists of QUERY_DIRECTORY + QUERY_INFO (FILE_ALL_INFORMATION) and the first command consumes nearly the entire max_trans_size, get_file_all_info() would blindly call smbConvertToUTF16() with PATH_MAX, causing out-of-bounds write beyond the response buffer. In get_file_all_info(), there was a missing validation check for the client-provided OutputBufferLength before copying the filename into FileName field of the smb2_file_all_info structure. If the filename length exceeds the available buffer space, it could lead to potential buffer overflows or memory corruption during smbConvertToUTF16 conversion. This calculating the actual free buffer size using smb2_calc_max_out_buf_len() and returning -EINVAL if the buffer is insufficient and updating smbConvertToUTF16 to use the actual filename length (clamped by PATH_MAX) to ensure a safe copy operation.",
"evidence": "osv:CVE-2026-31433",
"products": [
{
"name": {
"value": "Kernel",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.15.203",
"evidence": "/affected/1/ranges"
},
{
"value": "6.1.168",
"evidence": "/affected/1/ranges"
},
{
"value": "6.6.131",
"evidence": "/affected/1/ranges"
},
{
"value": "6.12.80",
"evidence": "/affected/1/ranges"
},
{
"value": "6.18.21",
"evidence": "/affected/1/ranges"
},
{
"value": "6.19.11",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "CVE-2026-31433",
"aliases": [
"CVE-2026-31433"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "f2283680a80571ca82d710bc6ecd8f8beac67d63"
},
{
"fixed": "3a852f9d1c981fb14f6bf4e24999e0ea8088a7d7"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "9f297df20d93411c0b4ddad7f88ba04a7cd36e77"
},
{
"fixed": "4cca3eff2099b18672934a39cee70aed835d652c"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d"
},
{
"fixed": "358cdaa1f7fbf2712cb4c5f6b59cb9a5c673c5fe"
},
{
"fixed": "7aec5a769d2356cbf344d85bcfd36de592ac96a5"
},
{
"fixed": "b0cd9725fe2bcc9f37d096b132318a9060373f5d"
},
{
"fixed": "9d7032851d6f5adbe2739601ca456c0ad3b422f0"
},
{
"fixed": "beef2634f81f1c086208191f7228bce1d366493d"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "5.15.145"
},
{
"fixed": "5.15.203"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.1.71"
},
{
"fixed": "6.1.168"
}
]
}
],
"versions": [
"v5.15.202",
"v5.15.201",
"v5.15.200",
"v5.15.199",
"v5.15.198",
"v5.15.197",
"v5.15.196",
"v5.15.195",
"v5.15.194",
"v5.15.193",
"v5.15.192",
"v5.15.191",
"v5.15.190",
"v5.15.189",
"v5.15.188",
"v5.15.187",
"v5.15.186",
"v5.15.185",
"v5.15.184",
"v5.15.183",
"v5.15.182",
"v5.15.181",
"v5.15.180",
"v5.15.179",
"v5.15.178",
"v5.15.177",
"v5.15.176",
"v5.15.175",
"v5.15.174",
"v5.15.173",
"v5.15.172",
"v5.15.171",
"v5.15.170",
"v5.15.169",
"v5.15.168",
"v5.15.167",
"v5.15.166",
"v5.15.165",
"v5.15.164",
"v5.15.163",
"v5.15.162",
"v5.15.161",
"v5.15.160",
"v5.15.159",
"v5.15.158",
"v5.15.157",
"v5.15.156",
"v5.15.155",
"v5.15.154",
"v5.15.153",
"v5.15.152",
"v5.15.151",
"v5.15.150",
"v5.15.149",
"v5.15.148",
"v5.15.147",
"v5.15.146",
"v5.15.145",
"v6.1.167",
"v6.1.166",
"v6.1.165",
"v6.1.164",
"v6.1.163",
"v6.1.162",
"v6.1.161",
"v6.1.160",
"v6.1.159",
"v6.1.158",
"v6.1.157",
"v6.1.156",
"v6.1.155",
"v6.1.154",
"v6.1.153",
"v6.1.152",
"v6.1.151",
"v6.1.150",
"v6.1.149",
"v6.1.148",
"v6.1.147",
"v6.1.146",
"v6.1.145",
"v6.1.144",
"v6.1.143",
"v6.1.142",
"v6.1.141",
"v6.1.140",
"v6.1.139",
"v6.1.138",
"v6.1.137",
"v6.1.136",
"v6.1.135",
"v6.1.134",
"v6.1.133",
"v6.1.132",
"v6.1.131",
"v6.1.130",
"v6.1.129",
"v6.1.128",
"v6.1.127",
"v6.1.126",
"v6.1.125",
"v6.1.124",
"v6.1.123",
"v6.1.122",
"v6.1.121",
"v6.1.120",
"v6.1.119",
"v6.1.118",
"v6.1.117",
"v6.1.116",
"v6.1.115",
"v6.1.114",
"v6.1.113",
"v6.1.112",
"v6.1.111",
"v6.1.110",
"v6.1.109",
"v6.1.108",
"v6.1.107",
"v6.1.106",
"v6.1.105",
"v6.1.104",
"v6.1.103",
"v6.1.102",
"v6.1.101",
"v6.1.100",
"v6.1.99",
"v6.1.98",
"v6.1.97",
"v6.1.96",
"v6.1.95",
"v6.1.94",
"v6.1.93",
"v6.1.92",
"v6.1.91",
"v6.1.90",
"v6.1.89",
"v6.1.88",
"v6.1.87",
"v6.1.86",
"v6.1.85",
"v6.1.84",
"v6.1.83",
"v6.1.82",
"v6.1.81",
"v6.1.80",
"v6.1.79",
"v6.1.78",
"v6.1.77",
"v6.1.76",
"v6.1.75",
"v6.1.74",
"v6.1.73",
"v6.1.72",
"v6.1.71"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31433.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.15.203"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "5.16.0"
},
{
"fixed": "6.1.168"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.2.0"
},
{
"fixed": "6.6.131"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.6.0"
},
{
"fixed": "6.12.80"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.7.0"
},
{
"fixed": "6.18.21"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.13.0"
},
{
"fixed": "6.19.11"
}
]
}
],
"package": {
"name": "Kernel",
"ecosystem": "Linux"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31433.json"
}
}
],
"modified": "2026-10-28T02:30:40.197618392Z",
"provider": "osv",
"references": [
"https://git.kernel.org/stable/c/358cdaa1f7fbf2712cb4c5f6b59cb9a5c673c5fe",
"https://git.kernel.org/stable/c/3a852f9d1c981fb14f6bf4e24999e0ea8088a7d7",
"https://git.kernel.org/stable/c/4cca3eff2099b18672934a39cee70aed835d652c",
"https://git.kernel.org/stable/c/7aec5a769d2356cbf344d85bcfd36de592ac96a5",
"https://git.kernel.org/stable/c/9d7032851d6f5adbe2739601ca456c0ad3b422f0",
"https://git.kernel.org/stable/c/b0cd9725fe2bcc9f37d096b132318a9060373f5d",
"https://git.kernel.org/stable/c/beef2634f81f1c086208191f7228bce1d366493d",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31433.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-31433",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31433.json"
}
},
"related_cves": [
{
"value": "CVE-2026-31433",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 507394,
"published_at": "2026-04-22T08:15:11.719+00:00"
}