diff options
author | Takashi Iwai <tiwai@suse.de> | 2012-10-16 13:05:59 +0200 |
---|---|---|
committer | Takashi Iwai <tiwai@suse.de> | 2012-10-30 11:07:10 +0100 |
commit | a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 (patch) | |
tree | 4dc74b708a07b56d12ed72a34d0a2e0cb8c8b9d4 /sound/core/oss/mixer_oss.c | |
parent | 888ea7d5ac6815ba16b3b3a20f665a92c7af6724 (diff) |
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 <matthieu.castet@parrot.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/oss/mixer_oss.c')
-rw-r--r-- | sound/core/oss/mixer_oss.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c index 29f6ded02555..a9a2e63c0222 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; |