[ALSA] snd_hwdep_release() racefix

snd_card_file_remove() can free the snd_card.
Touch hw->* only before calling snd_card_file_remove().
Unrelated: Allow hwdep devices not to have own ops.release();

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 5 insertions, 4 deletions

diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index a6a6ad0ad3c8..39c03f3dfbfa 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -156,15 +156,16 @@ static int snd_hwdep_release(struct inode *inode, struct file * file)
         int err = -ENXIO;
         struct snd_hwdep *hw = file->private_data;
         struct module *mod = hw->card->module;
+
         mutex_lock(&hw->open_mutex);
-        if (hw->ops.release) {
+        if (hw->ops.release)
                 err = hw->ops.release(hw, file);
-                wake_up(&hw->open_wait);
-        }
         if (hw->used > 0)
                 hw->used--;
-        snd_card_file_remove(hw->card, file);
         mutex_unlock(&hw->open_mutex);
+        wake_up(&hw->open_wait);
+
+        snd_card_file_remove(hw->card, file);
         module_put(mod);
         return err;
 }