4 files changed, 43 insertions, 18 deletions

diff --git a/sound/core/seq/oss/seq_oss.c b/sound/core/seq/oss/seq_oss.c
index 8cdf489df80e..ade880fe24a4 100644
--- a/sound/core/seq/oss/seq_oss.c
+++ b/sound/core/seq/oss/seq_oss.c
@@ -181,10 +181,19 @@ static long
 odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct seq_oss_devinfo *dp;
+	long rc;
+
 	dp = file->private_data;
 	if (snd_BUG_ON(!dp))
 		return -ENXIO;
-	return snd_seq_oss_ioctl(dp, cmd, arg);
+
+	if (cmd != SNDCTL_SEQ_SYNC &&
+	    mutex_lock_interruptible(&register_mutex))
+		return -ERESTARTSYS;
+	rc = snd_seq_oss_ioctl(dp, cmd, arg);
+	if (cmd != SNDCTL_SEQ_SYNC)
+		mutex_unlock(&register_mutex);
+	return rc;
 }
 
 #ifdef CONFIG_COMPAT
diff --git a/sound/core/seq/oss/seq_oss_synth.c b/sound/core/seq/oss/seq_oss_synth.c
index c93945917235..247b68790a52 100644
--- a/sound/core/seq/oss/seq_oss_synth.c
+++ b/sound/core/seq/oss/seq_oss_synth.c
@@ -624,7 +624,8 @@ snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_in
 
 	if (info->is_midi) {
 		struct midi_info minf;
-		snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf);
+		if (snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf))
+			return -ENXIO;
 		inf->synth_type = SYNTH_TYPE_MIDI;
 		inf->synth_subtype = 0;
 		inf->nr_voices = 16;
diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c
index c8fa4336bccd..86fb5eea9e4d 100644
--- a/sound/core/seq/seq_ports.c
+++ b/sound/core/seq/seq_ports.c
@@ -532,10 +532,11 @@ static int check_and_subscribe_port(struct snd_seq_client *client,
 	return err;
 }
 
-static void delete_and_unsubscribe_port(struct snd_seq_client *client,
-					struct snd_seq_client_port *port,
-					struct snd_seq_subscribers *subs,
-					bool is_src, bool ack)
+/* called with grp->list_mutex held */
+static void __delete_and_unsubscribe_port(struct snd_seq_client *client,
+					  struct snd_seq_client_port *port,
+					  struct snd_seq_subscribers *subs,
+					  bool is_src, bool ack)
 {
 	struct snd_seq_port_subs_info *grp;
 	struct list_head *list;
@@ -543,7 +544,6 @@ static void delete_and_unsubscribe_port(struct snd_seq_client *client,
 
 	grp = is_src ? &port->c_src : &port->c_dest;
 	list = is_src ? &subs->src_list : &subs->dest_list;
-	down_write(&grp->list_mutex);
 	write_lock_irq(&grp->list_lock);
 	empty = list_empty(list);
 	if (!empty)
@@ -553,6 +553,18 @@ static void delete_and_unsubscribe_port(struct snd_seq_client *client,
 
 	if (!empty)
 		unsubscribe_port(client, port, grp, &subs->info, ack);
+}
+
+static void delete_and_unsubscribe_port(struct snd_seq_client *client,
+					struct snd_seq_client_port *port,
+					struct snd_seq_subscribers *subs,
+					bool is_src, bool ack)
+{
+	struct snd_seq_port_subs_info *grp;
+
+	grp = is_src ? &port->c_src : &port->c_dest;
+	down_write(&grp->list_mutex);
+	__delete_and_unsubscribe_port(client, port, subs, is_src, ack);
 	up_write(&grp->list_mutex);
 }
 
@@ -608,27 +620,30 @@ int snd_seq_port_disconnect(struct snd_seq_client *connector,
 			    struct snd_seq_client_port *dest_port,
 			    struct snd_seq_port_subscribe *info)
 {
-	struct snd_seq_port_subs_info *src = &src_port->c_src;
+	struct snd_seq_port_subs_info *dest = &dest_port->c_dest;
 	struct snd_seq_subscribers *subs;
 	int err = -ENOENT;
 
-	down_write(&src->list_mutex);
+	/* always start from deleting the dest port for avoiding concurrent
+	 * deletions
+	 */
+	down_write(&dest->list_mutex);
 	/* look for the connection */
-	list_for_each_entry(subs, &src->list_head, src_list) {
+	list_for_each_entry(subs, &dest->list_head, dest_list) {
 		if (match_subs_info(info, &subs->info)) {
-			atomic_dec(&subs->ref_count); /* mark as not ready */
+			__delete_and_unsubscribe_port(dest_client, dest_port,
+						      subs, false,
+						      connector->number != dest_client->number);
 			err = 0;
 			break;
 		}
 	}
-	up_write(&src->list_mutex);
+	up_write(&dest->list_mutex);
 	if (err < 0)
 		return err;
 
 	delete_and_unsubscribe_port(src_client, src_port, subs, true,
 				    connector->number != src_client->number);
-	delete_and_unsubscribe_port(dest_client, dest_port, subs, false,
-				    connector->number != dest_client->number);
 	kfree(subs);
 	return 0;
 }
diff --git a/sound/core/seq/seq_queue.h b/sound/core/seq/seq_queue.h
index 719093489a2c..7909cf6040e3 100644
--- a/sound/core/seq/seq_queue.h
+++ b/sound/core/seq/seq_queue.h
@@ -40,10 +40,10 @@ struct snd_seq_queue {
 	
 	struct snd_seq_timer *timer;	/* time keeper for this queue */
 	int	owner;		/* client that 'owns' the timer */
-	unsigned int	locked:1,	/* timer is only accesibble by owner if set */
-		klocked:1,	/* kernel lock (after START) */	
-		check_again:1,
-		check_blocked:1;
+	bool	locked;		/* timer is only accesibble by owner if set */
+	bool	klocked;	/* kernel lock (after START) */
+	bool	check_again;	/* concurrent access happened during check */
+	bool	check_blocked;	/* queue being checked */
 
 	unsigned int flags;		/* status flags */
 	unsigned int info_flags;	/* info for sync */