{"id":"CVE-2025-68304","summary":"Bluetooth: hci_core: lookup hci_conn on RX path on protocol side","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: lookup hci_conn on RX path on protocol side\n\nThe hdev lock/lookup/unlock/use pattern in the packet RX path doesn't\nensure hci_conn* is not concurrently modified/deleted. This locking\nappears to be leftover from before conn_hash started using RCU\ncommit bf4c63252490b (\"Bluetooth: convert conn hash to RCU\")\nand not clear if it had purpose since then.\n\nCurrently, there are code paths that delete hci_conn* from elsewhere\nthan the ordered hdev-\u003eworkqueue where the RX work runs in. E.g.\ncommit 5af1f84ed13a (\"Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync\")\nintroduced some of these, and there probably were a few others before\nit.  It's better to do the locking so that even if these run\nconcurrently no UAF is possible.\n\nMove the lookup of hci_conn and associated socket-specific conn to\nprotocol recv handlers, and do them within a single critical section\nto cover hci_conn* usage and lookup.\n\nsyzkaller has reported a crash that appears to be this issue:\n\n    [Task hdev-\u003eworkqueue]          [Task 2]\n                                    hci_disconnect_all_sync\n    l2cap_recv_acldata(hcon)\n                                      hci_conn_get(hcon)\n                                      hci_abort_conn_sync(hcon)\n                                        hci_dev_lock\n      hci_dev_lock\n                                        hci_conn_del(hcon)\n      v-------------------------------- hci_dev_unlock\n                                      hci_conn_put(hcon)\n      conn = hcon-\u003el2cap_data (UAF)","modified":"2026-05-15T04:14:11.928471522Z","published":"2025-12-16T15:06:21.887Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68304.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/79a2d4678ba90bdba577dc3af88cc900d6dcd5ee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68304.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68304"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.6.0"},{"fixed":"6.17.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-68304.json"}}],"schema_version":"1.7.5"}