Hi Coiby, > When two HCI_EV_CONN_COMPLETE event packets with status=0 of the same > HCI connection are received, device_add would be called twice which > leads to kobject_add being called twice. Thus duplicate > (struct hci_conn *conn)->dev.kobj.entry would be inserted into > (struct hci_conn *conn)->dev.kobj.kset->list. > > This issue can be fixed by checking (struct hci_conn *conn)->debugfs. > If it's not NULL, it means the HCI connection has been completed and we > won't duplicate the work as for processing the first > HCI_EV_CONN_COMPLETE event. do you have a btmon trace for this happening? > Reported-and-tested-by: syzbot+dd768a260f7358adbaf9@xxxxxxxxxxxxxxxxxxxxxxxxx > Link: https://syzkaller.appspot.com/bug?extid=dd768a260f7358adbaf9 > Signed-off-by: Coiby Xu <coiby.xu@xxxxxxxxx> > --- > net/bluetooth/hci_event.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > index 4b7fc430793c..1233739ce760 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -2605,6 +2605,11 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb) > } > > if (!ev->status) { > + if (conn->debugfs) { > + bt_dev_err(hdev, "The connection has been completed"); > + goto unlock; > + } > + And instead of doing papering over a hole, I would rather detect that the HCI event is not valid since we already received one for this connection. Regards Marcel
