--- zzzz-none-000/linux-4.4.60/sound/core/seq/seq_clientmgr.c	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-7490-727/linux-4.4.60/sound/core/seq/seq_clientmgr.c	2021-02-04 17:41:59.000000000 +0000
@@ -1260,6 +1260,7 @@
 	struct snd_seq_client_port *port;
 	struct snd_seq_port_info info;
 	struct snd_seq_port_callback *callback;
+	int port_idx;
 
 	if (copy_from_user(&info, arg, sizeof(info)))
 		return -EFAULT;
@@ -1273,7 +1274,9 @@
 		return -ENOMEM;
 
 	if (client->type == USER_CLIENT && info.kernel) {
-		snd_seq_delete_port(client, port->addr.port);
+		port_idx = port->addr.port;
+		snd_seq_port_unlock(port);
+		snd_seq_delete_port(client, port_idx);
 		return -EINVAL;
 	}
 	if (client->type == KERNEL_CLIENT) {
@@ -1294,6 +1297,7 @@
 
 	snd_seq_set_port_info(port, &info);
 	snd_seq_system_client_ev_port_start(port->addr.client, port->addr.port);
+	snd_seq_port_unlock(port);
 
 	if (copy_to_user(arg, &info, sizeof(info)))
 		return -EFAULT;