{"id":"CVE-2026-99011","summary":"Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata()\n\nsco_recv_scodata() upgrades the weak hcon-\u003esco_data back-pointer to a\nstrong reference under hdev-\u003elock:\n\n    hci_dev_lock(hdev);\n    hcon = hci_conn_hash_lookup_handle(hdev, handle);\n    ...\n    conn = sco_conn_hold_unless_zero(hcon-\u003esco_data);\n    hci_dev_unlock(hdev);\n\nbut the pointer is cleared from the other side without that lock. When\nthe last sco_conn reference is dropped, sco_conn_free() ran\n\n    conn-\u003ehcon-\u003esco_data = NULL;\n\nwith no hdev-\u003elock held, so the RX path could read hcon-\u003esco_data and\ncall kref_get_unless_zero() on an sco_conn that was concurrently freed:\n\n    BUG: KASAN: slab-use-after-free in sco_conn_hold_unless_zero+0xbe/0x160\n    Write of size 4 by task kworker/u17:0\n    Workqueue: hci0 hci_rx_work\n    Call Trace:\n     sco_conn_hold_unless_zero+0xbe/0x160\n     sco_recv_scodata+0x13f/0x490\n     hci_rx_work+0x3af/0x730\n\nkref_get_unless_zero() only guards against a zero refcount, not against\nthe backing memory already being freed.\n\nGive hcon-\u003esco_data an actual reference on the sco_conn it points to, so\nthe object cannot be freed while the pointer is still installed, and only\nclear and drop it from sco_conn_del(), which runs under hdev-\u003elock (its\ncallers, sco_connect_cfm() and sco_disconn_cfm(), hold it). The reader in\nsco_recv_scodata() also takes hdev-\u003elock, so the store and the read are\nnow serialised: the RX path either observes NULL or a reference that is\nguaranteed to stay valid until it drops its own.\n\nsco_conn_add() no longer hands its kref_init() reference to the caller as\nthe connection's only reference; that initial reference is the one owned\nby hcon-\u003esco_data, and callers get their own via sco_conn_hold().\n\nBecause the sco_conn can now outlive the socket (the association keeps it\nalive until the link goes down), the hci_conn can no longer be dropped\nfrom sco_conn_free() without regressing socket close: closing a connected\nSCO socket must still tear the link down. Move hci_conn ownership to the\nsocket instead: __sco_chan_add() takes an hci_conn reference and it is\nreleased from sco_chan_del() and sco_sock_destruct(), exactly once. The\nsco_conn no longer owns an hci_conn reference, so sco_conn_add() stops\nconsuming one and sco_connect() drops the hci_connect_sco() reference on\nevery path; sco_connect_cfm() no longer needs its hci_conn_hold() dance.","modified":"2026-11-12T17:29:12.694426368Z","published":"2026-10-23T12:20:36.460Z","related":["SUSE-SU-2026:24643-1","SUSE-SU-2026:24648-1","SUSE-SU-2026:24651-1","SUSE-SU-2026:24662-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99011.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/816fb1590a4c8cf8d05cd076057616be02e276f0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8a98d58f6cfe70d51138cd9ce894e72671d95f8a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b108ea7ebba147465f4158d8133f0e8f013762ed"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99011.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99011"},{"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":"e6720779ae612a14ac4ba7fe4fd5b27d900d932c"},{"fixed":"b108ea7ebba147465f4158d8133f0e8f013762ed"},{"fixed":"8a98d58f6cfe70d51138cd9ce894e72671d95f8a"},{"fixed":"816fb1590a4c8cf8d05cd076057616be02e276f0"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99011.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.57"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99011.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}