{"id":"CVE-2026-64404","summary":"Bluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync()\n\niso_conn_big_sync() drops the socket lock to call hci_get_route() and\nthen re-acquires it, but dereferences iso_pi(sk)-\u003econn-\u003ehcon afterwards\nwithout re-checking that conn is still valid.\n\nWhile the lock is dropped, the connection can be torn down under the\nsame socket lock: iso_disconn_cfm() -\u003e iso_conn_del() -\u003e iso_chan_del()\nsets iso_pi(sk)-\u003econn to NULL (and the broadcast teardown path can also\nclear conn-\u003ehcon on its own). When iso_conn_big_sync() re-acquires the\nlock and reads conn-\u003ehcon, conn may be NULL, causing a NULL pointer\ndereference (hcon is the first member of struct iso_conn).\n\nThis path is reached from iso_sock_recvmsg() for a PA-sync broadcast\nsink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock\nwindow can race with connection teardown driven by controller events.\n\nRe-validate iso_pi(sk)-\u003econn and its hcon after re-acquiring the socket\nlock and bail out if the connection went away, as already done in the\nsibling iso_sock_rebind_bc().","modified":"2026-07-27T04:03:20.000689988Z","published":"2026-07-25T08:50:46.523Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64404.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/01afd198c2c286cd3b81f44d4e33a2e638711550"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b3e647a4aa4d2d054f86a783f5c426035e1dc237"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b84eeb7636d6962dd882d5e0b31475e4f404313c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d5541eb148da72d5e0a1bca8ecd171f9fc8b366f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64404.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64404"},{"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":"cbe640d6cae590b9a7d81ce86fe9a90e83eec1d5"},{"fixed":"b3e647a4aa4d2d054f86a783f5c426035e1dc237"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"7a17308c17880d259105f6e591eb1bc77b9612f0"},{"fixed":"b84eeb7636d6962dd882d5e0b31475e4f404313c"},{"fixed":"01afd198c2c286cd3b81f44d4e33a2e638711550"},{"fixed":"d5541eb148da72d5e0a1bca8ecd171f9fc8b366f"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.12.6"},{"fixed":"6.12.96"}]}],"versions":["v6.12.95","v6.12.94","v6.12.93","v6.12.92","v6.12.91","v6.12.90","v6.12.89","v6.12.88","v6.12.87","v6.12.86","v6.12.85","v6.12.84","v6.12.83","v6.12.82","v6.12.81","v6.12.80","v6.12.79","v6.12.78","v6.12.77","v6.12.76","v6.12.75","v6.12.74","v6.12.73","v6.12.72","v6.12.71","v6.12.70","v6.12.69","v6.12.68","v6.12.67","v6.12.66","v6.12.65","v6.12.64","v6.12.63","v6.12.62","v6.12.61","v6.12.60","v6.12.59","v6.12.58","v6.12.57","v6.12.56","v6.12.55","v6.12.54","v6.12.53","v6.12.52","v6.12.51","v6.12.50","v6.12.49","v6.12.48","v6.12.47","v6.12.46","v6.12.45","v6.12.44","v6.12.43","v6.12.42","v6.12.41","v6.12.40","v6.12.39","v6.12.38","v6.12.37","v6.12.36","v6.12.35","v6.12.34","v6.12.33","v6.12.32","v6.12.31","v6.12.30","v6.12.29","v6.12.28","v6.12.27","v6.12.26","v6.12.25","v6.12.24","v6.12.23","v6.12.22","v6.12.21","v6.12.20","v6.12.19","v6.12.18","v6.12.17","v6.12.16","v6.12.15","v6.12.14","v6.12.13","v6.12.12","v6.12.11","v6.12.10","v6.12.9","v6.12.8","v6.12.7","v6.12.6"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64404.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.96"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.39"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64404.json"}}],"schema_version":"1.7.5"}