[alsa-devel] [PATCH] ASoC: Intel: skl_hda_dsp_common: Fix global-out-of-bounds bug

[Sridharan, Ranjani]

On Wed, Jan 22, 2020 at 2:50 PM Pierre-Louis Bossart <
pierre-louis.bossart at linux.intel.com> wrote:

>
> >> Kai and Ranjani, do you think this impacts SOF as well? Or does our BE
> >> override somehow suppresses the problem?
> >>
> > Hi Pierre/Cezary,
> >
> > SOF does have the same problem too but I thought we're allowed to have
> dai
> > links without platform component? An alternative to adding the platform
> > component would be to do something like below.
> >
> > Thanks,
> > Ranjani
> > diff --git a/sound/soc/intel/boards/skl_hda_dsp_generic.c
> > b/sound/soc/intel/boards/skl_hda_dsp_generic.c
> > index 11eaee9ae41f..dacf8014b870 100644
> > --- a/sound/soc/intel/boards/skl_hda_dsp_generic.c
> > +++ b/sound/soc/intel/boards/skl_hda_dsp_generic.c
> > @@ -112,6 +112,7 @@ static char hda_soc_components[30];
> >
> >   static int skl_hda_fill_card_info(struct snd_soc_acpi_mach_params
> > *mach_params)
> >   {
> > +       struct snd_soc_dai_link_component *platform;
> >          struct snd_soc_card *card = &hda_soc_card;
> >          struct snd_soc_dai_link *dai_link;
> >          u32 codec_count, codec_mask;
> > @@ -148,7 +149,8 @@ static int skl_hda_fill_card_info(struct
> > snd_soc_acpi_mach_params *mach_params)
> >          card->num_dapm_routes = num_route;
> >
> >          for_each_card_prelinks(card, i, dai_link)
> > -               dai_link->platforms->name = mach_params->platform;
> > +               for_each_link_platforms(dai_link, i, platform)
> > +                       platform->name = mach_params->platform;
>
> we already do this indirectly with:
>
> skl_hda_add_dai_link(struct snd_soc_card *card, struct snd_soc_dai_link
> *link)
> {
>         link->platforms->name = ctx->platform_name; <<<
>
> I suspect the issue is that the plaforms part is not allocated. The
> 8-byte out of bounds is not a string, it looks like a pointer stored in
> the wrong location.
>
skl_hda_fill_card_info() would be called before skl_hda_add_dai_link(). But
yes, it should be fixed here as well or as suggested in the patch, we
should set the platform component to prevent this error.

Thanks,
Ranjani