Re: [syzbot] [bluetooth?] general protection fault in h4_recv

[Edward Adam Davis]

#syz test

diff --git a/drivers/bluetooth/hci_h4.c b/drivers/bluetooth/hci_h4.c
index a889a66a326f..07cc2a79a77b 100644
--- a/drivers/bluetooth/hci_h4.c
+++ b/drivers/bluetooth/hci_h4.c
@@ -109,6 +109,9 @@ static int h4_recv(struct hci_uart *hu, const void *data, int count)
 {
 	struct h4_struct *h4 = hu->priv;
 
+	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
+		return -EUNATCH;
+
 	h4->rx_skb = h4_recv_buf(hu, h4->rx_skb, data, count,
 				 h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts));
 	if (IS_ERR(h4->rx_skb)) {