D-Bus(old): Fix removeNetwork and selectNetwork error handling

wpas_dbus_decompose_object_path() may leave the network part NULL on
unexpected path. This resulted in NULL pointer dereference when
processing an invalid removeNetwork or selectNetwork call. Fix this by
explicitly verifying that the network part was included in the object
path.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/dbus/dbus_old_handlers.c

@@ -846,7 +846,7 @@ DBusMessage * wpas_dbus_iface_remove_network(DBusMessage *message,
 
 	/* Extract the network ID */
 	iface = wpas_dbus_decompose_object_path(op, &net_id, NULL);
-	if (iface == NULL) {
+	if (iface == NULL || net_id == NULL) {
 		reply = wpas_dbus_new_invalid_network_error(message);
 		goto out;
 	}
@@ -1102,7 +1102,8 @@ DBusMessage * wpas_dbus_iface_select_network(DBusMessage *message,
 			goto out;
 		}
 		/* Ensure the object path really points to this interface */
-		if (os_strcmp(iface_obj_path, wpa_s->dbus_path) != 0) {
+		if (network == NULL ||
+		    os_strcmp(iface_obj_path, wpa_s->dbus_path) != 0) {
 			reply = wpas_dbus_new_invalid_network_error(message);
 			goto out;
 		}