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

[Pierre-Louis Bossart]

>> 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.