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: firefly_0821_release~7541^2~333
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=aaf238baf31e14cb1c111815193c3a78770b1873;p=firefly-linux-kernel-4.4.55.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 5cdd0fe7109e..e7c118389015 100644
--- a/sound/core/oss/mixer_oss.c
+++ b/sound/core/oss/mixer_oss.c
@@ -75,6 +75,7 @@ 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 ea757241f47b..725a16135988 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 c8e5a6b6c756..7393551a8c47 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -2110,7 +2110,8 @@ 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;
 }
 
@@ -2123,7 +2124,8 @@ 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 b235aaa3a1bf..e9b79b531082 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 cdeae29f43fb..b6ff6d6349f0 100644
--- a/sound/core/sound_oss.c
+++ b/sound/core/sound_oss.c
@@ -53,7 +53,7 @@ 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;