Merge tag 'sound-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "The amount of the changes isn't as quite small as wished, nevertheless
  they are straight fixes that deserve merging to 4.14 final.

  Most of fixes are about ALSA core bugs spotted by fuzzer: a follow-up
  fix for the previous nested rwsem patch, a fix to avoid the resource
  hogs due to too many concurrent ALSA timer invocations, and a fix for
  a crash with SYSEX MIDI transfer over OSS sequencer emulation that is
  used by none but fuzzer.

  The rest are usual HD-audio and USB-audio device-specific quirks,
  which are safe to apply"

* tag 'sound-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - fix headset mic problem for Dell machines with alc274
  ALSA: seq: Fix OSS sysex delivery in OSS emulation
  ALSA: seq: Avoid invalid lockdep class warning
  ALSA: timer: Limit max instances per timer
  ALSA: usb-audio: support new Amanero Combo384 firmware version

1 files changed, 54 insertions, 13 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 6cdd04a45962..15e82a656d96 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -180,7 +180,7 @@ static void snd_timer_request(struct snd_timer_id *tid)
  *
  * call this with register_mutex down.
  */
-static void snd_timer_check_slave(struct snd_timer_instance *slave)
+static int snd_timer_check_slave(struct snd_timer_instance *slave)
 {
 	struct snd_timer *timer;
 	struct snd_timer_instance *master;
@@ -190,16 +190,21 @@ static void snd_timer_check_slave(struct snd_timer_instance *slave)
 		list_for_each_entry(master, &timer->open_list_head, open_list) {
 			if (slave->slave_class == master->slave_class &&
 			    slave->slave_id == master->slave_id) {
+				if (master->timer->num_instances >=
+				    master->timer->max_instances)
+					return -EBUSY;
 				list_move_tail(&slave->open_list,
 					       &master->slave_list_head);
+				master->timer->num_instances++;
 				spin_lock_irq(&slave_active_lock);
 				slave->master = master;
 				slave->timer = master->timer;
 				spin_unlock_irq(&slave_active_lock);
-				return;
+				return 0;
 			}
 		}
 	}
+	return 0;
 }
 
 /*
@@ -208,7 +213,7 @@ static void snd_timer_check_slave(struct snd_timer_instance *slave)
  *
  * call this with register_mutex down.
  */
-static void snd_timer_check_master(struct snd_timer_instance *master)
+static int snd_timer_check_master(struct snd_timer_instance *master)
 {
 	struct snd_timer_instance *slave, *tmp;
 
@@ -216,7 +221,11 @@ static void snd_timer_check_master(struct snd_timer_instance *master)
 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
 		if (slave->slave_class == master->slave_class &&
 		    slave->slave_id == master->slave_id) {
+			if (master->timer->num_instances >=
+			    master->timer->max_instances)
+				return -EBUSY;
 			list_move_tail(&slave->open_list, &master->slave_list_head);
+			master->timer->num_instances++;
 			spin_lock_irq(&slave_active_lock);
 			spin_lock(&master->timer->lock);
 			slave->master = master;
@@ -228,8 +237,11 @@ static void snd_timer_check_master(struct snd_timer_instance *master)
 			spin_unlock_irq(&slave_active_lock);
 		}
 	}
+	return 0;
 }
 
+static int snd_timer_close_locked(struct snd_timer_instance *timeri);
+
 /*
  * open a timer instance
  * when opening a master, the slave id must be here given.
@@ -240,6 +252,7 @@ int snd_timer_open(struct snd_timer_instance **ti,
 {
 	struct snd_timer *timer;
 	struct snd_timer_instance *timeri = NULL;
+	int err;
 
 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 		/* open a slave instance */
@@ -259,10 +272,14 @@ int snd_timer_open(struct snd_timer_instance **ti,
 		timeri->slave_id = tid->device;
 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
-		snd_timer_check_slave(timeri);
+		err = snd_timer_check_slave(timeri);
+		if (err < 0) {
+			snd_timer_close_locked(timeri);
+			timeri = NULL;
+		}
 		mutex_unlock(&register_mutex);
 		*ti = timeri;
-		return 0;
+		return err;
 	}
 
 	/* open a master instance */
@@ -288,6 +305,10 @@ int snd_timer_open(struct snd_timer_instance **ti,
 			return -EBUSY;
 		}
 	}
+	if (timer->num_instances >= timer->max_instances) {
+		mutex_unlock(&register_mutex);
+		return -EBUSY;
+	}
 	timeri = snd_timer_instance_new(owner, timer);
 	if (!timeri) {
 		mutex_unlock(&register_mutex);
@@ -314,25 +335,27 @@ int snd_timer_open(struct snd_timer_instance **ti,
 	}
 
 	list_add_tail(&timeri->open_list, &timer->open_list_head);
-	snd_timer_check_master(timeri);
+	timer->num_instances++;
+	err = snd_timer_check_master(timeri);
+	if (err < 0) {
+		snd_timer_close_locked(timeri);
+		timeri = NULL;
+	}
 	mutex_unlock(&register_mutex);
 	*ti = timeri;
-	return 0;
+	return err;
 }
 EXPORT_SYMBOL(snd_timer_open);
 
 /*
  * close a timer instance
+ * call this with register_mutex down.
  */
-int snd_timer_close(struct snd_timer_instance *timeri)
+static int snd_timer_close_locked(struct snd_timer_instance *timeri)
 {
 	struct snd_timer *timer = NULL;
 	struct snd_timer_instance *slave, *tmp;
 
-	if (snd_BUG_ON(!timeri))
-		return -ENXIO;
-
-	mutex_lock(&register_mutex);
 	list_del(&timeri->open_list);
 
 	/* force to stop the timer */
@@ -340,6 +363,7 @@ int snd_timer_close(struct snd_timer_instance *timeri)
 
 	timer = timeri->timer;
 	if (timer) {
+		timer->num_instances--;
 		/* wait, until the active callback is finished */
 		spin_lock_irq(&timer->lock);
 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
@@ -355,6 +379,7 @@ int snd_timer_close(struct snd_timer_instance *timeri)
 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 					 open_list) {
 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
+			timer->num_instances--;
 			slave->master = NULL;
 			slave->timer = NULL;
 			list_del_init(&slave->ack_list);
@@ -382,9 +407,24 @@ int snd_timer_close(struct snd_timer_instance *timeri)
 		module_put(timer->module);
 	}
 
-	mutex_unlock(&register_mutex);
 	return 0;
 }
+
+/*
+ * close a timer instance
+ */
+int snd_timer_close(struct snd_timer_instance *timeri)
+{
+	int err;
+
+	if (snd_BUG_ON(!timeri))
+		return -ENXIO;
+
+	mutex_lock(&register_mutex);
+	err = snd_timer_close_locked(timeri);
+	mutex_unlock(&register_mutex);
+	return err;
+}
 EXPORT_SYMBOL(snd_timer_close);
 
 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
@@ -856,6 +896,7 @@ int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 	spin_lock_init(&timer->lock);
 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
 		     (unsigned long)timer);
+	timer->max_instances = 1000; /* default limit per timer */
 	if (card != NULL) {
 		timer->module = card->module;
 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);