{"id":"CVE-2026-23231","summary":"netfilter: nf_tables: fix use-after-free in nf_tables_addchain()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: fix use-after-free in nf_tables_addchain()\n\nnf_tables_addchain() publishes the chain to table-\u003echains via\nlist_add_tail_rcu() (in nft_chain_add()) before registering hooks.\nIf nf_tables_register_hook() then fails, the error path calls\nnft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy()\nwith no RCU grace period in between.\n\nThis creates two use-after-free conditions:\n\n 1) Control-plane: nf_tables_dump_chains() traverses table-\u003echains\n    under rcu_read_lock(). A concurrent dump can still be walking\n    the chain when the error path frees it.\n\n 2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly\n    installs the IPv4 hook before IPv6 registration fails.  Packets\n    entering nft_do_chain() via the transient IPv4 hook can still be\n    dereferencing chain-\u003eblob_gen_X when the error path frees the\n    chain.\n\nAdd synchronize_rcu() between nft_chain_del() and the chain destroy\nso that all RCU readers -- both dump threads and in-flight packet\nevaluation -- have finished before the chain is freed.","modified":"2026-04-03T11:04:11.934246Z","published":"2026-03-04T12:58:42.029Z","related":["openSUSE-SU-2026:10387-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23231.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2a6586ecfa4ce1413daaafee250d2590e05f1a33"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7017745068a9068904e1e7a1b170a5785647cc81"},{"type":"WEB","url":"https://git.kernel.org/stable/c/71e99ee20fc3f662555118cf1159443250647533"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dbd0af8083dd201f07c49110b2ee93710abdff28"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f3fe58ce37926a10115ede527d59b91bcc05400a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23231.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23231"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"91c7b38dc9f0de4f7f444b796d14476bc12df7bc"},{"fixed":"2a6586ecfa4ce1413daaafee250d2590e05f1a33"},{"fixed":"7017745068a9068904e1e7a1b170a5785647cc81"},{"fixed":"f3fe58ce37926a10115ede527d59b91bcc05400a"},{"fixed":"dbd0af8083dd201f07c49110b2ee93710abdff28"},{"fixed":"2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b"},{"fixed":"71e99ee20fc3f662555118cf1159443250647533"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23231.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}