{"id":"CVE-2023-52924","summary":"netfilter: nf_tables: don't skip expired elements during walk","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: don't skip expired elements during walk\n\nThere is an asymmetry between commit/abort and preparation phase if the\nfollowing conditions are met:\n\n1. set is a verdict map (\"1.2.3.4 : jump foo\")\n2. timeouts are enabled\n\nIn this case, following sequence is problematic:\n\n1. element E in set S refers to chain C\n2. userspace requests removal of set S\n3. kernel does a set walk to decrement chain-\u003euse count for all elements\n   from preparation phase\n4. kernel does another set walk to remove elements from the commit phase\n   (or another walk to do a chain-\u003euse increment for all elements from\n    abort phase)\n\nIf E has already expired in 1), it will be ignored during list walk, so its use count\nwon't have been changed.\n\nThen, when set is culled, -\u003edestroy callback will zap the element via\nnf_tables_set_elem_destroy(), but this function is only safe for\nelements that have been deactivated earlier from the preparation phase:\nlack of earlier deactivate removes the element but leaks the chain use\ncount, which results in a WARN splat when the chain gets removed later,\nplus a leak of the nft_chain structure.\n\nUpdate pipapo_get() not to skip expired elements, otherwise flush\ncommand reports bogus ENOENT errors.","modified":"2026-04-03T13:14:37.472135202Z","published":"2025-02-05T09:07:55.418Z","related":["SUSE-SU-2025:02264-1","SUSE-SU-2025:02321-1","SUSE-SU-2025:02322-1","SUSE-SU-2025:02537-1","SUSE-SU-2025:0784-1","SUSE-SU-2025:0834-1","SUSE-SU-2025:0847-1","SUSE-SU-2025:0855-1","SUSE-SU-2025:0856-1","SUSE-SU-2025:0867-1","SUSE-SU-2025:0955-1","SUSE-SU-2025:20190-1","SUSE-SU-2025:20192-1","SUSE-SU-2025:20260-1","SUSE-SU-2025:20270-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52924.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1da4874d05da1526b11b82fc7f3c7ac38749ddf8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/24138933b97b055d486e8064b4a1721702442a9b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/59dab3bf0b8fc08eb802721c0532f13dd89209b8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c7e658a36f8b1522bd3586d8137e5f93a25ddc5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/94313a196b44184b5b52c1876da6a537701b425a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b15ea4017af82011dd55225ce77cce3d4dfc169c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bd156ce9553dcaf2d6ee2c825d1a5a1718e86524"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52924.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-52924"},{"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":"9d0982927e79049675cb6c6c04a0ebb3dad5a434"},{"fixed":"94313a196b44184b5b52c1876da6a537701b425a"},{"fixed":"1da4874d05da1526b11b82fc7f3c7ac38749ddf8"},{"fixed":"b15ea4017af82011dd55225ce77cce3d4dfc169c"},{"fixed":"7c7e658a36f8b1522bd3586d8137e5f93a25ddc5"},{"fixed":"59dab3bf0b8fc08eb802721c0532f13dd89209b8"},{"fixed":"bd156ce9553dcaf2d6ee2c825d1a5a1718e86524"},{"fixed":"24138933b97b055d486e8064b4a1721702442a9b"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-52924.json"}}],"schema_version":"1.7.5"}