CVE-2025-40268 (GCVE-0-2025-40268)

Vulnerability from cvelistv5 – Published: 2025-12-06 21:50 – Updated: 2026-10-30 12:22
VLAI
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
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7033 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 299bc05e1475a4aa1eb985ade8f39e68c1bba9b9 (git)
Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 868fc62811d3fabcf5685e14f36377a855d5412d (git)
Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 48c17341577e25a22feb13d694374b61d974edbc (git)
Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < 4515743cc7a42e1d67468402a6420c195532a6fa (git)
Affected: af1a3d2ba9543e99d78914d8fb88b61d0531d9a1 , < e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6 (git)
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Linux Linux Affected: 5.11
Unaffected: 0 , < 5.11 (semver)
Unaffected: 6.1.191 , ≤ 6.1.* (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)
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      "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"
        }
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      "providerMetadata": {
        "dateUpdated": "2026-10-30T12:22:57.829Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/299bc05e1475a4aa1eb985ade8f39e68c1bba9b9"
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        {
          "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",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40268",
    "datePublished": "2025-12-06T21:50:48.917Z",
    "dateReserved": "2025-04-16T07:20:57.183Z",
    "dateUpdated": "2026-10-30T12:22:57.829Z",
    "state": "PUBLISHED"
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      "date": "2026-10-30",
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      "percentile": "0.08378"
    },
    "microsoft_vex": {
      "current_release_date": "2025-12-16T14:37:14.000Z",
      "cve": "CVE-2025-40268",
      "id": "msrc_CVE-2025-40268",
      "initial_release_date": "2025-12-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "cifs: client: fix memory leak in smb3_fs_context_parse_param",
      "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-40268.json",
      "version": "3"
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        "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"
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha corregido la siguiente vulnerabilidad:\n\ncifs: cliente: corregir fuga de memoria en?\u0027smb3_fs_context_parse_param\u0027\n\nEl usuario llama a fsconfig dos veces, pero cuando el programa finaliza,?\u0027free()\u0027 solo libera \u0027ctx -\u003e source\u0027 para el segundo?fsconfig, no para el primero. En cuanto a \u0027fc -\u003e source\u0027, no existe c\u00f3digo en el contexto de fs relacionado con la reclamaci\u00f3n de su memoria.\n\nPara corregir esta fuga de memoria, libere la memoria?source correspondiente a?\u0027ctx\u0027 o a?\u0027fc\u0027 antes de cada an\u00e1lisis.\n\nsyzbot inform\u00f3:\n\u0027\u0027\u0027\nBUG: fuga de memoria\nobjeto sin referencias 0xffff888128afa360 (tama\u00f1o 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: fuga de memoria\nobjeto sin referencias 0xffff888112c7d900 (tama\u00f1o 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\n\u0027\u0027\u0027"
          }
        ],
        "id": "CVE-2025-40268",
        "lastModified": "2026-10-30T13:18:14.560",
        "metrics": {},
        "published": "2025-12-06T22:15:54.327",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        "vulnStatus": "Deferred"
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      "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"
    }
  }
}



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