Re: [syzbot] Re: [syzbot] [bluetooth?] general protection fault in qca_close

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Subject: Re: [syzbot] [bluetooth?] general protection fault in qca_close
Author: lizhi.xu@xxxxxxxxxxxxx

if hci register device lose than clear HCI_UART_PROTO_READY bit.
And move closer set bit HCI_UART_PROTO_READY to hci_register_dev, make the window smaller.

#syz test

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index b955dc96b483..d5b97ff59330 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -683,8 +683,10 @@ static int hci_uart_register_dev(struct hci_uart *hu)
 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 		return 0;
 
+	set_bit(HCI_UART_PROTO_READY, &hu->flags);
 	if (hci_register_dev(hdev) < 0) {
 		BT_ERR("Can't register HCI device");
+		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 		hu->proto->close(hu);
 		hu->hdev = NULL;
 		hci_free_dev(hdev);
@@ -707,8 +709,6 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id)
 
 	hu->proto = p;
 
-	set_bit(HCI_UART_PROTO_READY, &hu->flags);
-
 	err = hci_uart_register_dev(hu);
 	if (err) {
 		return err;