HCI_EV_PHY_LINK_COMPLETE in net/bluetooth/hci_event.c

[Fox Chen]

Dear all,

I have a question about

static void hci_phy_link_complete_evt(struct hci_dev *hdev,
struct sk_buff *skb)
-- HCI_EV_PHY_LINK_COMPLETE event packet handler in hci_even.c:4940

if (ev->status) {
        hci_conn_del(hcon);                 <--------------
        hci_dev_unlock(hdev);
        return;
}

Is it correct to del hcon here?? Because later on, when we close the
socket fd, socket_close will call sco_chan_del which will eventually
call hci_conn_drop. With hcon already deleted by this handler, it will
crash.

This bug is reported by syzbot in
https://syzkaller.appspot.com/bug?id=57e98513afbe427bbd65ac295130bcf5bc860dd8

I'm trying to fix that, but I don't know the design nature of
HCI_EV_PHY_LINK_COMPLETE. Will this scenario happen in real life?? Can
I remove hci_conn_del(hcon) here (I tested it, which fixes this bug)
??


Thanks,
Fox