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/hwdep.c | |
| parent | ALSA: usb-audio: Fix races at disconnection in mixer_quirks.c (diff) | |
| download | linux-a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85.tar.xz linux-a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85.zip | |
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/hwdep.c')
| -rw-r--r-- | sound/core/hwdep.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c index 75ea16f35b1a..53a6ba5ad615 100644 --- a/sound/core/hwdep.c +++ b/sound/core/hwdep.c @@ -100,8 +100,10 @@ static int snd_hwdep_open(struct inode *inode, struct file * file) if (hw == NULL) return -ENODEV; - if (!try_module_get(hw->card->module)) + if (!try_module_get(hw->card->module)) { + snd_card_unref(hw->card); return -EFAULT; + } init_waitqueue_entry(&wait, current); add_wait_queue(&hw->open_wait, &wait); @@ -148,6 +150,7 @@ static int snd_hwdep_open(struct inode *inode, struct file * file) mutex_unlock(&hw->open_mutex); if (err < 0) module_put(hw->card->module); + snd_card_unref(hw->card); return err; } |