Re: [PATCH] ALSA: aoa: i2sbus: fix possible memory leak in i2sbus_add_dev()

[Takashi Iwai <tiwai@suse.de>]

On Thu, 27 Oct 2022 09:41:03 +0200,
Yang Yingliang wrote:
> 
> 
> On 2022/10/27 14:38, Takashi Iwai wrote:
> > On Thu, 27 Oct 2022 03:34:38 +0200,
> > Yang Yingliang wrote:
> >> dev_set_name() in soundbus_add_one() allocates memory for name, it need be
> >> freed when of_device_register() fails, call soundbus_dev_put() to give up
> >> the reference that hold in device_initialize(), so that it can be freed in
> >> kobject_cleanup() when the refcount hit to 0. And other resources are also
> >> freed in i2sbus_release_dev(), so it can return 0 directly.
> >> 
> >> Fixes: f3d9478b2ce4 ("[ALSA] snd-aoa: add snd-aoa")
> >> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> > The check of kobj state is awkward, but it seems to be the simplest
> > way...  Applied now.  Thanks!
> 
> Indeed, it's awkward, shall we introduce a helper like this:
> 
> diff --git a/sound/aoa/soundbus/i2sbus/core.c
> b/sound/aoa/soundbus/i2sbus/core.c
> index f6841daf9e3b..950c37e0297e 100644
> --- a/sound/aoa/soundbus/i2sbus/core.c
> +++ b/sound/aoa/soundbus/i2sbus/core.c
> @@ -302,7 +302,7 @@ static int i2sbus_add_dev(struct macio_dev *macio,
> 
>         if (soundbus_add_one(&dev->sound)) {
>                 printk(KERN_DEBUG "i2sbus: device registration error!\n");
> -               if (dev->sound.ofdev.dev.kobj.state_initialized) {
> +               if (soundbus_dev_initialized(&dev->sound)) {
>                         soundbus_dev_put(&dev->sound);
>                         return 0;
>                 }
> diff --git a/sound/aoa/soundbus/soundbus.h b/sound/aoa/soundbus/soundbus.h
> index 3a99c1f1a3ca..2c9c95cf156a 100644
> --- a/sound/aoa/soundbus/soundbus.h
> +++ b/sound/aoa/soundbus/soundbus.h
> @@ -174,6 +174,10 @@ struct soundbus_dev {
> 
>  extern int soundbus_add_one(struct soundbus_dev *dev);
>  extern void soundbus_remove_one(struct soundbus_dev *dev);
> +static inline bool soundbus_dev_initialized(struct soundbus_dev *dev)
> +{
> +       return dev->ofdev.dev.kobj.state_initialized;
> +}

I think it's not worth much as it's used only at a single place.


Takashi