{"id":"CVE-2026-98581","title":"nfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm()","summary":"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->conne…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < dd2d24add86b3b63cd87cf2feff98ae119ba19a6","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 812731dd8511f5768f4ff279b3c18d85cd21da4b","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < c1e9ed52a6697354366dddf190fbacee8ed2f7c5","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 7fb2c0eeb79bfad64065f539a453138abd0edda6","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < b94cf09720543cc34256c7aa88f8059cbe7c0419","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1","Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < bf1460acdf8cf5a07c819f59785d40f20d113099","Linux 3.6"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:18:54.696Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98581","references":[{"url":"https://git.kernel.org/stable/c/dd2d24add86b3b63cd87cf2feff98ae119ba19a6"},{"url":"https://git.kernel.org/stable/c/812731dd8511f5768f4ff279b3c18d85cd21da4b"},{"url":"https://git.kernel.org/stable/c/dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08"},{"url":"https://git.kernel.org/stable/c/c1e9ed52a6697354366dddf190fbacee8ed2f7c5"},{"url":"https://git.kernel.org/stable/c/7fb2c0eeb79bfad64065f539a453138abd0edda6"},{"url":"https://git.kernel.org/stable/c/b94cf09720543cc34256c7aa88f8059cbe7c0419"},{"url":"https://git.kernel.org/stable/c/320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1"},{"url":"https://git.kernel.org/stable/c/bf1460acdf8cf5a07c819f59785d40f20d113099"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.253Z","slug":"CVE-2026-98581","body":"## Overview\n\nIn 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->connecting_sockets: it looks the socket up with\nnfc_llcp_connecting_sock_get(), sets sk->sk_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->sockets, 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.\n\n## Affected\n\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < dd2d24add86b3b63cd87cf2feff98ae119ba19a6`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 812731dd8511f5768f4ff279b3c18d85cd21da4b`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < c1e9ed52a6697354366dddf190fbacee8ed2f7c5`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 7fb2c0eeb79bfad64065f539a453138abd0edda6`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < b94cf09720543cc34256c7aa88f8059cbe7c0419`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1`\n- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < bf1460acdf8cf5a07c819f59785d40f20d113099`\n- `Linux 3.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}