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/control.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/control.c')
| -rw-r--r-- | sound/core/control.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/sound/core/control.c b/sound/core/control.c index 7e86a5b9f3b..9768a3963c8 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -86,6 +86,7 @@ static int snd_ctl_open(struct inode *inode, struct file *file) write_lock_irqsave(&card->ctl_files_rwlock, flags); list_add_tail(&ctl->list, &card->ctl_files); write_unlock_irqrestore(&card->ctl_files_rwlock, flags); + snd_card_unref(card); return 0; __error: @@ -93,6 +94,8 @@ static int snd_ctl_open(struct inode *inode, struct file *file) __error2: snd_card_file_remove(card, file); __error1: + if (card) + snd_card_unref(card); return err; } |