[PATCH] sound: hdmi: avoid dereferencing uninitialized 'jack' pointer

Arnd Bergmann
2016-02-16T22:08:13Z

On Tuesday 16 February 2016 18:26:09 Arnd Bergmann wrote:
> > return err;
> > per_pin->acomp_jack = jack;
> > - jack->private_data = per_pin;
> > - jack->private_free = free_acomp_jack_priv;
> > + if (jack) {
> > + jack->private_data = per_pin;
> > + jack->private_free = free_acomp_jack_priv;
> > + }
> > return 0;
> > }
> >
> Looks good to me.
>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
>

Actually, on second thought, there is one notable downside
of this approach: 'jack' is guaranteed to be NULL here, so gcc
won't produce a warning if another driver makes the same mistake:

By default, we only get a warning for uses of uninitialized
variables, but not those that are known to be NULL. I think
some compiler warnings are able to warn about that too, but I
forgot the details.

Arnd