{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-40271", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.183Z", "datePublished": "2025-12-06T21:50:53.266Z", "dateUpdated": "2026-05-11T21:46:07.444Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:46:07.444Z"}, "descriptions": [{"lang": "en", "value": "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": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/proc/generic.c"], "versions": [{"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "1d1596d68a6f11d28f677eedf6cf5b17dbfeb491", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "c81d0385500446efe48c305bbb83d47f2ae23a50", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "4cba73c4c89219beef7685a47374bf88b1022369", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "6f2482745e510ae1dacc9b090194b9c5f918d774", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "67272c11f379d9aa5e0f6b16286b9d89b3f76046", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "623bb26127fb581a741e880e1e1a47d79aecb6f8", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "03de7ff197a3d0e17d0d5c58fdac99a63cba8110", "status": "affected", "versionType": "git"}, {"version": "710585d4922fd315f2cada8fbe550ae8ed23e994", "lessThan": "895b4c0c79b092d732544011c3cecaf7322c36a1", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/proc/generic.c"], "versions": [{"version": "3.19", "status": "affected"}, {"version": "0", "lessThan": "3.19", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.302", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.247", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.197", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.159", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.117", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.59", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17.9", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "5.4.302"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "5.10.247"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "5.15.197"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.1.159"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.6.117"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.12.59"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.17.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.18"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1d1596d68a6f11d28f677eedf6cf5b17dbfeb491"}, {"url": "https://git.kernel.org/stable/c/c81d0385500446efe48c305bbb83d47f2ae23a50"}, {"url": "https://git.kernel.org/stable/c/4cba73c4c89219beef7685a47374bf88b1022369"}, {"url": "https://git.kernel.org/stable/c/6f2482745e510ae1dacc9b090194b9c5f918d774"}, {"url": "https://git.kernel.org/stable/c/67272c11f379d9aa5e0f6b16286b9d89b3f76046"}, {"url": "https://git.kernel.org/stable/c/623bb26127fb581a741e880e1e1a47d79aecb6f8"}, {"url": "https://git.kernel.org/stable/c/03de7ff197a3d0e17d0d5c58fdac99a63cba8110"}, {"url": "https://git.kernel.org/stable/c/895b4c0c79b092d732544011c3cecaf7322c36a1"}], "title": "fs/proc: fix uaf in proc_readdir_de()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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)"}], "id": "CVE-2025-40271", "lastModified": "2026-04-15T00:35:42.020", "metrics": {}, "published": "2025-12-06T22:15:54.737", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/03de7ff197a3d0e17d0d5c58fdac99a63cba8110"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1d1596d68a6f11d28f677eedf6cf5b17dbfeb491"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4cba73c4c89219beef7685a47374bf88b1022369"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/623bb26127fb581a741e880e1e1a47d79aecb6f8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/67272c11f379d9aa5e0f6b16286b9d89b3f76046"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6f2482745e510ae1dacc9b090194b9c5f918d774"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/895b4c0c79b092d732544011c3cecaf7322c36a1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c81d0385500446efe48c305bbb83d47f2ae23a50"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Deferred"}

{"bugzilla": {"description": "kernel: fs/proc: fix uaf in proc_readdir_de()", "id": "2419837", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2419837"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nfs/proc: fix uaf in proc_readdir_de()\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.\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:\n1) use getdent to traverse dir /proc/pid/net/dev_snmp6/, and current\npde is tun3;\n2) in the [time windows] unregister netdevice tun3 and tun2, and erase\nthem from rbtree. erase tun3 first, and then erase tun2. the\npde(tun2) will be released to slab;\n3) continue to getdent process, then pde_subdir_next() will return\npde(tun2) which is released, it will case uaf access.\nCPU 0 | CPU 1\n-------------------------------------------------------------------------\ntraverse dir /proc/pid/net/dev_snmp6/ | unregister_netdevice(tun->dev) //tun3 tun2\nsys_getdents64() |\niterate_dir() |\nproc_readdir() |\nproc_readdir_de() | snmp6_unregister_dev()\npde_get(de); | proc_remove()\nread_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);\nread_lock(&proc_subdir_lock); |\nnext = pde_subdir_next(de); |\npde_put(de); |\nde = next; //UAF |\nrbtree of dev_snmp6\n|\npde(tun3)\n/ \\\nNULL pde(tun2)"], "name": "CVE-2025-40271", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-12-06T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-40271\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-40271\nhttps://lore.kernel.org/linux-cve-announce/2025120716-CVE-2025-40271-7612@gregkh/T"], "threat_severity": "Important"}

{}