{"id":"CVE-2026-89684","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-89684","summary":"nfsd: fix cpntf publish race in nfs4_init_cp_state","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix cpntf publish race in nfs4_init_cp_state\n\nnfs4_alloc_init_cpntf_state() published the new cpntf entry into the\ns2s_cp_stateids IDR (with cs_type set) in one s2s_cp_lock section, then\ntook the lock again to list_add() it onto p_stid->sc_cp_list. In the gap\nthe entry is reachable by so_id but cp_list is still {NULL,NULL} from\nkzalloc. A racing OFFLOAD_CANCEL (so_id is echoed to the client as\ncnr_stateid, so any NFSv4.2 client can drive it) reaches\nmanage_cpntf_state() -> _free_cpntf_state_locked() and does list_del() on\nthe zeroed list_head, oopsing the server.\n\nFold the cs_type assignment and the list_add() into the same critical\nsection as idr_alloc_cyclic(), so a concurrent lookup either misses the\nentry or sees a fully linked cp_list. INIT_LIST_HEAD() the entry after\nallocation and switch _free_cpntf_state_locked() to list_del_init() so a\nstale unlink is a no-op. nfs4_init_copy_state() passes NULL p_stid and\nskips the list_add, preserving NFS4_COPY_STID semantics.","published":"2026-09-11T19:46:06.374Z","modified":"2026-09-14T03:46:25.164600783Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.12.109"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a631a26a8777bb235eabd478bbbaf26a4db750bf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be3a5c1d857b0dcbc11796cea603ef25834f75b2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c7270f62e7a05a2ee68aa2b74262b658a14463bd"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89684.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89684"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-14T03:46:25.164600783Z"}}