out-of-bounds access in sound/soc/sof/topology.c

[Sergey Senozhatsky]

On (22/04/19 08:07), Pierre-Louis Bossart wrote:
> > Your analyzes are spot on, unfortunately. But...
> > 
> > As of today, the sof_get_control_data() is in the call path of
> > (ipc3-topology.c):
> > 
> > sof_widget_update_ipc_comp_process() -> sof_process_load() ->
> > sof_get_control_data()
> > 
> > sof_widget_update_ipc_comp_process() is the ipc_setup callback for
> > snd_soc_dapm_effect. If I'm not mistaken these only carries bin payload
> > and never MIXER/ENUM/SWITCH/VOLUME.
> > This means that the sof_get_control_data() is only called with
> > SND_SOC_TPLG_TYPE_BYTES and for that the allocated data area is correct.
> > 
> > This can explain why we have not seen any issues so far. This does not
> > renders the code right, as how it is written atm is wrong.
> 
> 
> Sergey's results with KASAN show that there's a real-life problem though. I also don't understand how that might happen.
> 
> Could it be that these results are with a specific topology where our assumptions are incorrect?

Is there anything I can do to help?