ALSA: seq: Fix OOB-reads from strlcpy

BugLink: https://bugs.launchpad.net/bugs/1828420

commit 212ac181 upstream.

When ioctl calls are made with non-null-terminated userspace strings,
strlcpy causes an OOB-read from within strlen. Fix by changing to use
strscpy instead.
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

sound/core/seq/seq_clientmgr.c

@@ -1249,7 +1249,7 @@ static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client,
 
 	/* fill the info fields */
 	if (client_info.name[0])
-		strlcpy(client->name, client_info.name, sizeof(client->name));
+		strscpy(client->name, client_info.name, sizeof(client->name));
 
 	client->filter = client_info.filter;
 	client->event_lost = client_info.event_lost;
@@ -1558,7 +1558,7 @@ static int snd_seq_ioctl_create_queue(struct snd_seq_client *client,
 	/* set queue name */
 	if (! info.name[0])
 		snprintf(info.name, sizeof(info.name), "Queue-%d", q->queue);
-	strlcpy(q->name, info.name, sizeof(q->name));
+	strscpy(q->name, info.name, sizeof(q->name));
 	snd_use_lock_free(&q->use_lock);
 
 	if (copy_to_user(arg, &info, sizeof(info)))
@@ -1636,7 +1636,7 @@ static int snd_seq_ioctl_set_queue_info(struct snd_seq_client *client,
 		queuefree(q);
 		return -EPERM;
 	}
-	strlcpy(q->name, info.name, sizeof(q->name));
+	strscpy(q->name, info.name, sizeof(q->name));
 	queuefree(q);
 
 	return 0;