{"id":"AZL-108833","summary":"CVE-2026-98581 affecting package kernel 6.6.157.1-1","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":"2026-10-20T05:35:13Z","published":"2026-10-18T16:17:10Z","upstream":["CVE-2026-98581"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98581"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-108833.json"}}],"schema_version":"1.9.0"}