[ALSA] Dereference after free in snd_hwdep_release()

snd_card_file_remove() may free hw->card so we can't dereference
hw->card->module after that.
Coverity ID 1420.

Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index 618c43be0bc36e35cd9915fe9652c36ebd3f3fc6..c3845f6eedcebad20e7791a3ff658d90e355f4f8 100644 (file)
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -157,6 +157,7 @@ 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;
        down(&hw->open_mutex);
        if (hw->ops.release) {
                err = hw->ops.release(hw, file);
@@ -166,7 +167,7 @@ static int snd_hwdep_release(struct inode *inode, struct file * file)
                hw->used--;
        snd_card_file_remove(hw->card, file);
        up(&hw->open_mutex);
-       module_put(hw->card->module);
+       module_put(mod);
        return err;
 }