From 40edba667959559aa4385a5ec047420fcfeb5f03 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 7 Nov 2012 12:44:12 +0100 Subject: ALSA: Add a reference counter to card instance commit a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 upstream. For more strict protection for wild disconnections, a refcount is introduced to the card instance, and let it up/down when an object is referred via snd_lookup_*() in the open ops. The free-after-last-close check is also changed to check this refcount instead of the empty list, too. Reported-by: Matthieu CASTET Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/rawmidi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'sound/core/rawmidi.c') diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index cbbed0d..69935c0 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -394,8 +394,10 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) if (rmidi == NULL) return -ENODEV; - if (!try_module_get(rmidi->card->module)) + if (!try_module_get(rmidi->card->module)) { + snd_card_unref(rmidi->card); return -ENXIO; + } mutex_lock(&rmidi->open_mutex); card = rmidi->card; @@ -455,6 +457,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) #endif file->private_data = rawmidi_file; mutex_unlock(&rmidi->open_mutex); + snd_card_unref(rmidi->card); return 0; __error: @@ -462,6 +465,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) __error_card: mutex_unlock(&rmidi->open_mutex); module_put(rmidi->card->module); + snd_card_unref(rmidi->card); return err; } -- cgit v1.1