Re: [alsa-devel] [RFC PATCH 06/40] soundwire: intel: prevent possible dereference in hw_params

[Pierre-Louis Bossart]

On 8/2/19 6:55 AM, Vinod Koul wrote:
> On 25-07-19, 18:39, Pierre-Louis Bossart wrote:
> > This should not happen in production systems but we should test for
> > all callback arguments before invoking the config_stream callback.
>
> so you are saying callback arg is mandatory, if so please document that
> assumption

no, what this says is that if a config_stream is provided then it needs 
to have a valid argument.

I am not sure what you mean by "document that assumption", comment in 
the code (where?) or SoundWire documentation?

> > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> > ---
> >   drivers/soundwire/intel.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
> > index 68832e613b1e..497879dd9c0d 100644
> > --- a/drivers/soundwire/intel.c
> > +++ b/drivers/soundwire/intel.c
> > @@ -509,7 +509,7 @@ static int intel_config_stream(struct sdw_intel *sdw,
> >   			       struct snd_soc_dai *dai,
> >   			       struct snd_pcm_hw_params *hw_params, int link_id)
> >   {
> > -	if (sdw->res->ops && sdw->res->ops->config_stream)
> > +	if (sdw->res->ops && sdw->res->ops->config_stream && sdw->res->arg)
> >   		return sdw->res->ops->config_stream(sdw->res->arg,
> >   				substream, dai, hw_params, link_id);
> >   
> > --
> > 2.20.1