diff options
| author | Takashi Iwai <tiwai@suse.de> | 2012-11-07 12:42:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-17 13:16:13 -0800 |
| commit | 41a496238dae4c117548be819b0a3b3edbc48dc8 (patch) | |
| tree | 83190bcf55b89b79825b2f98ae493db4428f9885 /sound/core/oss | |
| parent | 1c694ffc72666085a5ad880fef913ee2c8c69c4a (diff) | |
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 <matthieu.castet@parrot.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/core/oss')
| -rw-r--r-- | sound/core/oss/mixer_oss.c | 10 | ||||
| -rw-r--r-- | sound/core/oss/pcm_oss.c | 2 |
2 files changed, 10 insertions, 2 deletions
diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c index 18297f7f2c5..05395aaeaa3 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 08fde0060fd..2529e01538e 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; } |