ALSA: fireworks/bebob/dice/oxfw: allow stream destructor after releasing runtime

Currently stream destructor in each driver has a problem to be called in
a context in which sound card object is released, because the destructors
call amdtp_stream_pcm_abort() and touch PCM runtime data.

The PCM runtime data is destroyed in application's context with
snd_pcm_close(), on the other hand PCM substream data is destroyed after
sound card object is released, in most case after all of ALSA character
devices are released. When PCM runtime is destroyed and PCM substream is
remained, amdtp_stream_pcm_abort() touches PCM runtime data and causes
Null-pointer-dereference.

This commit changes stream destructors and allows each driver to call
it after releasing runtime.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: <stable@vger.kernel.org> # 3.19+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 12 insertions, 6 deletions

diff --git a/sound/firewire/dice/dice-stream.c b/sound/firewire/dice/dice-stream.c
index fa9cf761b610..07dbd01d7a6b 100644
--- a/sound/firewire/dice/dice-stream.c
+++ b/sound/firewire/dice/dice-stream.c
@@ -311,14 +311,21 @@ end:
 	return err;
 }
 
+/*
+ * This function should be called before starting streams or after stopping
+ * streams.
+ */
 static void destroy_stream(struct snd_dice *dice, struct amdtp_stream *stream)
 {
-	amdtp_stream_destroy(stream);
+	struct fw_iso_resources *resources;
 
 	if (stream == &dice->tx_stream)
-		fw_iso_resources_destroy(&dice->tx_resources);
+		resources = &dice->tx_resources;
 	else
-		fw_iso_resources_destroy(&dice->rx_resources);
+		resources = &dice->rx_resources;
+
+	amdtp_stream_destroy(stream);
+	fw_iso_resources_destroy(resources);
 }
 
 int snd_dice_stream_init_duplex(struct snd_dice *dice)
@@ -332,6 +339,8 @@ int snd_dice_stream_init_duplex(struct snd_dice *dice)
 		goto end;
 
 	err = init_stream(dice, &dice->rx_stream);
+	if (err < 0)
+		destroy_stream(dice, &dice->tx_stream);
 end:
 	return err;
 }
@@ -340,10 +349,7 @@ void snd_dice_stream_destroy_duplex(struct snd_dice *dice)
 {
 	snd_dice_transaction_clear_enable(dice);
 
-	stop_stream(dice, &dice->tx_stream);
 	destroy_stream(dice, &dice->tx_stream);
-
-	stop_stream(dice, &dice->rx_stream);
 	destroy_stream(dice, &dice->rx_stream);
 
 	dice->substreams_counter = 0;