From a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 16 Oct 2012 13:05:59 +0200 Subject: ALSA: Add a reference counter to card instance 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 Cc: Signed-off-by: Takashi Iwai --- sound/core/oss/mixer_oss.c | 10 ++++++++-- sound/core/oss/pcm_oss.c | 2 ++ 2 files changed, 10 insertions(+), 2 deletions(-) (limited to 'sound/core/oss') diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c index 29f6ded..a9a2e63 100644 --- a/sound/core/oss/mixer_oss.c +++ b/sound/core/oss/mixer_oss.c @@ -52,14 +52,19 @@ static int snd_mixer_oss_open(struct inode *inode, struct file *file) SNDRV_OSS_DEVICE_TYPE_MIXER); if (card == NULL) return -ENODEV; - if (card->mixer_oss == NULL) + if (card->mixer_oss == NULL) { + snd_card_unref(card); return -ENODEV; + } err = snd_card_file_add(card, file); - if (err < 0) + if (err < 0) { + snd_card_unref(card); return err; + } fmixer = kzalloc(sizeof(*fmixer), GFP_KERNEL); if (fmixer == NULL) { snd_card_file_remove(card, file); + snd_card_unref(card); return -ENOMEM; } fmixer->card = card; @@ -68,6 +73,7 @@ static int snd_mixer_oss_open(struct inode *inode, struct file *file) if (!try_module_get(card->module)) { kfree(fmixer); snd_card_file_remove(card, file); + snd_card_unref(card); return -EFAULT; } return 0; diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index 08fde00..2529e01 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -2457,6 +2457,8 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file) __error2: snd_card_file_remove(pcm->card, file); __error1: + if (pcm) + snd_card_unref(pcm->card); return err; } -- cgit v1.1