From: Takashi Iwai <tiwai@suse.de>
Date: Thu, 8 Nov 2012 13:36:18 +0000 (+0100)
Subject: ALSA: Fix card refcount unbalance
X-Git-Tag: v3.4.19~2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=32896690903c576809f21724115612a82a102a52;p=karo-tx-linux.git

ALSA: Fix card refcount unbalance

commit 8bb4d9ce08b0a92ca174e41d92c180328f86173f upstream.

There are uncovered cases whether the card refcount introduced by the
commit a0830dbd isn't properly increased or decreased:
- OSS PCM and mixer success paths
- When lookup function gets NULL

This patch fixes these places.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=50251

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c
index 05395aaeaa32..c353768854e6 100644
--- a/sound/core/oss/mixer_oss.c
+++ b/sound/core/oss/mixer_oss.c
@@ -76,6 +76,7 @@ static int snd_mixer_oss_open(struct inode *inode, struct file *file)
 		snd_card_unref(card);
 		return -EFAULT;
 	}
+	snd_card_unref(card);
 	return 0;
 }
 
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index f337b66a020b..4c1cc51772e6 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2454,6 +2454,7 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file)
 	mutex_unlock(&pcm->open_mutex);
 	if (err < 0)
 		goto __error;
+	snd_card_unref(pcm->card);
 	return err;
 
       __error:
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 0844444eb100..d535b341aa82 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -2111,7 +2111,8 @@ static int snd_pcm_playback_open(struct inode *inode, struct file *file)
 	pcm = snd_lookup_minor_data(iminor(inode),
 				    SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
 	err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_PLAYBACK);
-	snd_card_unref(pcm->card);
+	if (pcm)
+		snd_card_unref(pcm->card);
 	return err;
 }
 
@@ -2124,7 +2125,8 @@ static int snd_pcm_capture_open(struct inode *inode, struct file *file)
 	pcm = snd_lookup_minor_data(iminor(inode),
 				    SNDRV_DEVICE_TYPE_PCM_CAPTURE);
 	err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_CAPTURE);
-	snd_card_unref(pcm->card);
+	if (pcm)
+		snd_card_unref(pcm->card);
 	return err;
 }
 
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 7c0640eeee52..3700d96fb3fb 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -115,7 +115,7 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
 	mreg = snd_minors[minor];
 	if (mreg && mreg->type == type) {
 		private_data = mreg->private_data;
-		if (mreg->card_ptr)
+		if (private_data && mreg->card_ptr)
 			atomic_inc(&mreg->card_ptr->refcount);
 	} else
 		private_data = NULL;
diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c
index 7442c7ac2469..ec86009141d0 100644
--- a/sound/core/sound_oss.c
+++ b/sound/core/sound_oss.c
@@ -54,7 +54,7 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type)
 	mreg = snd_oss_minors[minor];
 	if (mreg && mreg->type == type) {
 		private_data = mreg->private_data;
-		if (mreg->card_ptr)
+		if (private_data && mreg->card_ptr)
 			atomic_inc(&mreg->card_ptr->refcount);
 	} else
 		private_data = NULL;