{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2025-40271",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-40271",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-12-06T21:50:53.266Z",
    "updatedAt": "2026-08-05T12:09:04.518Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "fs/proc: fix uaf in proc_readdir_de()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc: fix uaf in proc_readdir_de()\n\nPde is erased from subdir rbtree through rb_erase(), but not set the node\nto EMPTY, which may result in uaf access.  We should use RB_CLEAR_NODE()\nset the erased node to EMPTY, then pde_subdir_next() will return NULL to\navoid uaf access.\n\nWe found an uaf issue while using stress-ng testing, need to run testcase\ngetdent and tun in the same time.  The steps of the issue is as follows:\n\n1) use getdent to traverse dir /proc/pid/net/dev_snmp6/, and current\n   pde is tun3;\n\n2) in the [time windows] unregister netdevice tun3 and tun2, and erase\n   them from rbtree.  erase tun3 first, and then erase tun2.  the\n   pde(tun2) will be released to slab;\n\n3) continue to getdent process, then pde_subdir_next() will return\n   pde(tun2) which is released, it will case uaf access.\n\nCPU 0                                      |    CPU 1\n-------------------------------------------------------------------------\ntraverse dir /proc/pid/net/dev_snmp6/      |   unregister_netdevice(tun->dev)   //tun3 tun2\nsys_getdents64()                           |\n  iterate_dir()                            |\n    proc_readdir()                         |\n      proc_readdir_de()                    |     snmp6_unregister_dev()\n        pde_get(de);                       |       proc_remove()\n        read_unlock(&proc_subdir_lock);    |         remove_proc_subtree()\n                                           |           write_lock(&proc_subdir_lock);\n        [time window]                      |           rb_erase(&root->subdir_node, &parent->subdir);\n                                           |           write_unlock(&proc_subdir_lock);\n        read_lock(&proc_subdir_lock);      |\n        next = pde_subdir_next(de);        |\n        pde_put(de);                       |\n        de = next;    //UAF                |\n\nrbtree of dev_snmp6\n                        |\n                    pde(tun3)\n                     /    \\\n                  NULL  pde(tun2)",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1d1596d68a6f11d28f677eedf6cf5b17dbfeb491"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c81d0385500446efe48c305bbb83d47f2ae23a50"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4cba73c4c89219beef7685a47374bf88b1022369"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6f2482745e510ae1dacc9b090194b9c5f918d774"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "67272c11f379d9aa5e0f6b16286b9d89b3f76046"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "623bb26127fb581a741e880e1e1a47d79aecb6f8"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "03de7ff197a3d0e17d0d5c58fdac99a63cba8110"
            },
            {
              "version": "710585d4922fd315f2cada8fbe550ae8ed23e994",
              "status": "affected",
              "versionType": "git",
              "lessThan": "895b4c0c79b092d732544011c3cecaf7322c36a1"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "3.19",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "3.19"
            },
            {
              "version": "5.4.302",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.247",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.197",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.159",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.117",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.59",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.17.9",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.17.*"
            },
            {
              "version": "6.18",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}