diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index b5b78d469d54f6..d097e308a7554f 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -2180,7 +2180,15 @@ static bool hci_conn_check_create_big_sync(struct hci_conn *conn)
 	return true;
 }
 
-int hci_le_big_create_sync_pending(struct hci_dev *hdev)
+static void big_create_sync_complete(struct hci_dev *hdev, void *data, int err)
+{
+	bt_dev_dbg(hdev, "");
+
+	if (err)
+		bt_dev_err(hdev, "Unable to create BIG sync: %d", err);
+}
+
+static int big_create_sync(struct hci_dev *hdev, void *data)
 {
 	DEFINE_FLEX(struct hci_cp_le_big_create_sync, pdu, bis, num_bis, 0x11);
 	struct hci_conn *conn;
@@ -2237,6 +2245,13 @@ int hci_le_big_create_sync_pending(struct hci_dev *hdev)
 			    struct_size(pdu, bis, pdu->num_bis), pdu);
 }
 
+int hci_le_big_create_sync_pending(struct hci_dev *hdev)
+{
+	/* Queue big_create_sync */
+	return hci_cmd_sync_queue_once(hdev, big_create_sync,
+				       NULL, big_create_sync_complete);
+}
+
 int hci_le_big_create_sync(struct hci_dev *hdev, struct hci_conn *hcon,
 			   struct bt_iso_qos *qos,
 			   __u16 sync_handle, __u8 num_bis, __u8 bis[])
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 24e78ada9ad232..1b40fd2b2f0208 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -1392,6 +1392,13 @@ static void iso_conn_big_sync(struct sock *sk)
 	if (!hdev)
 		return;
 
+	/* hci_le_big_create_sync requires hdev lock to be held, since
+	 * it enqueues the HCI LE BIG Create Sync command via
+	 * hci_cmd_sync_queue_once, which checks hdev flags that might
+	 * change.
+	 */
+	hci_dev_lock(hdev);
+
 	if (!test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) {
 		err = hci_le_big_create_sync(hdev, iso_pi(sk)->conn->hcon,
 					     &iso_pi(sk)->qos,
@@ -1402,6 +1409,8 @@ static void iso_conn_big_sync(struct sock *sk)
 			bt_dev_err(hdev, "hci_le_big_create_sync: %d",
 				   err);
 	}
+
+	hci_dev_unlock(hdev);
 }
 
 static int iso_sock_recvmsg(struct socket *sock, struct msghdr *msg,