{"id":"CVE-2026-98581","summary":"nfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm()\n\nnfc_llcp_recv_dm() handles DM(NOBOUND)/DM(REJ) for a socket that is still\nlinked on local-\u003econnecting_sockets: it looks the socket up with\nnfc_llcp_connecting_sock_get(), sets sk-\u003esk_state = LLCP_CLOSED and\nreturns, without taking the socket lock and without unlinking the socket\nfrom the connecting_sockets list.\n\nllcp_sock_release() selects the list to unlink from by sk_state: a socket\nin LLCP_CONNECTING is unlinked from connecting_sockets, otherwise from the\nsockets list.  Because recv_dm left the socket physically on\nconnecting_sockets but in the LLCP_CLOSED state, release() takes the else\nbranch and calls nfc_llcp_sock_unlink(&local-\u003esockets, sk).  That runs\nsk_del_node_init() while holding sockets.lock, i.e. it removes the socket\nfrom the connecting_sockets hlist under the wrong lock.  A concurrent\nconnect() linking another socket onto connecting_sockets under\nconnecting_sockets.lock then mutates the same hlist unserialized, which\ncorrupts the list and desyncs the sk_add_node()/sk_del_node_init()\nsock_hold()/__sock_put() pairing.  An unprivileged local process holding\nLLCP sockets, with the DM supplied by the remote peer over an established\nLLCP link, can drive this to leak kernel sockets without bound (the\nmis-decrement goes through the non-freeing __sock_put() path, so the\nobject is never released), leading to memory exhaustion / DoS.\n\nThis is the same class of bug that was fixed in the sibling handler\nnfc_llcp_recv_cc() by commit b493ea2765cc (\"nfc: llcp: Fix use-after-free\nrace in nfc_llcp_recv_cc()\"); recv_dm did not receive the equivalent fix.\n\nFix it the same way: take lock_sock(), re-check that the socket is still\nhashed (release() may have won the race), and for the NOBOUND/REJ case\nunlink it from connecting_sockets before moving it to LLCP_CLOSED.  The\nunlink drops the connecting_sockets membership reference via\nsk_del_node_init(), leaving the socket unhashed, so the later\nnfc_llcp_sock_unlink() in llcp_sock_release() becomes a no-op and no\ndouble put occurs.","modified":"2026-10-20T02:30:16.777093469Z","published":"2026-10-18T15:18:54.696Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98581.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fb2c0eeb79bfad64065f539a453138abd0edda6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/812731dd8511f5768f4ff279b3c18d85cd21da4b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b94cf09720543cc34256c7aa88f8059cbe7c0419"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bf1460acdf8cf5a07c819f59785d40f20d113099"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c1e9ed52a6697354366dddf190fbacee8ed2f7c5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dd2d24add86b3b63cd87cf2feff98ae119ba19a6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98581.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98581"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a69f32af86e389dd232b1bb2269e202c1bfcc60f"},{"fixed":"dd2d24add86b3b63cd87cf2feff98ae119ba19a6"},{"fixed":"812731dd8511f5768f4ff279b3c18d85cd21da4b"},{"fixed":"dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08"},{"fixed":"c1e9ed52a6697354366dddf190fbacee8ed2f7c5"},{"fixed":"7fb2c0eeb79bfad64065f539a453138abd0edda6"},{"fixed":"b94cf09720543cc34256c7aa88f8059cbe7c0419"},{"fixed":"320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1"},{"fixed":"bf1460acdf8cf5a07c819f59785d40f20d113099"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98581.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.6.0"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98581.json"}}],"schema_version":"1.9.0"}