6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aldo Ariel Panzardo commit 4c94557dd02569efa6c1072a0439addaef9a5224 upstream. hci_conn_link() takes a lifetime reference to its parent with hci_conn_get(), but only takes an operational hold on the child. hci_conn_unlink() later balances both a hold and a reference on the parent. The SCO and CIS paths pass a parent acquired from a connect helper, so it already has a hold. For an additional BIS, hci_bind_bis() obtains the parent from hci_conn_hash_lookup_big(), which returns a bare pointer. Unlinking the child then drops the parent's existing hold and can schedule it for disconnection while its socket is still using it. Take a hold on the parent before linking it and drop that hold if linking fails. A successful link transfers the hold to hci_conn_unlink(). Fixes: fa224d0c094a ("Bluetooth: ISO: Reassociate a socket with an active BIS") Cc: stable@vger.kernel.org Signed-off-by: Aldo Ariel Panzardo Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_conn.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -2273,10 +2273,13 @@ struct hci_conn *hci_bind_bis(struct hci parent = hci_conn_hash_lookup_big(hdev, conn->iso_qos.bcast.big); if (parent && parent != conn) { + hci_conn_hold(parent); link = hci_conn_link(parent, conn); hci_conn_drop(conn); - if (!link) + if (!link) { + hci_conn_drop(parent); return ERR_PTR(-ENOLINK); + } } return conn;