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

Takashi Iwai
2016-02-24T16:25:42Z

On Wed, 24 Feb 2016 17:18:58 +0100,
Arnd Bergmann wrote:
>
> On Wednesday 17 February 2016 10:35:40 Takashi Iwai wrote:
> > On Wed, 17 Feb 2016 10:03:50 +0100,
> > + const char *id;
> > +#ifdef CONFIG_SND_JACK_INPUT_DEV
> > + struct input_dev *input_dev;
> > int registered;
> > int type;
> > - const char *id;
> > char name[100];
> > unsigned int key[6]; /* Keep in sync with definitions above */
> > +#endif /* CONFIG_SND_JACK_INPUT_DEV */
> > void *private_data;
> > void (*private_free)(struct snd_jack *);
> > };
>
> I got a build error from this today, as the trace event tries to print
> the jack "name" field. I've managed to get it to build again by printing
> the "id" field in place of the "name". The name is normally assigned
> from id in snd_jack_dev_register using
>
> snprintf(jack->name, sizeof(jack->name), "%s %s",
> card->shortname, jack->id);
>
> but that code is not called here at all. My patch will slightly
> alter the output as a consequence, but I don't know if this change
> is critical or not.

Thanks for catching this. Yes, your fix is correct. This must have
been a wrong pick up when converting from the standalone hda jack to
unified jack stuff.

Could you send a proper patch for inclusion?

Takashi

>
> Arnd
>
> diff --git a/include/trace/events/asoc.h b/include/trace/events/asoc.h
> index 317a1ed2f4ac..9130dd5a184a 100644
> --- a/include/trace/events/asoc.h
> +++ b/include/trace/events/asoc.h
> @@ -231,13 +231,13 @@ TRACE_EVENT(snd_soc_jack_report,
> TP_ARGS(jack, mask, val),
>
> TP_STRUCT__entry(
> - __string( name, jack->jack->name )
> + __string( name, jack->jack->id )
> __field( int, mask )
> __field( int, val )
> ),
>
> TP_fast_assign(
> - __assign_str(name, jack->jack->name);
> + __assign_str(name, jack->jack->id);
> __entry->mask = mask;
> __entry->val = val;
> ),
> @@ -253,12 +253,12 @@ TRACE_EVENT(snd_soc_jack_notify,
> TP_ARGS(jack, val),
>
> TP_STRUCT__entry(
> - __string( name, jack->jack->name )
> + __string( name, jack->jack->id )
> __field( int, val )
> ),
>
> TP_fast_assign(
> - __assign_str(name, jack->jack->name);
> + __assign_str(name, jack->jack->id);
> __entry->val = val;
> ),
>
>