On Mon, Mar 25, 2019 at 07:21:00AM -0700, Guenter Roeck wrote:

> It is actually a bit more complicated than that. The stored pointer (drv->soc_card)
> isn't released. The problem is that dev_get_drvdata(drv->soc_card->dev) is NULL,
> which causes the crash. I don't think there is a UAF involved - I built the
> test image with KASAN enabled and it did not barf at me.

What is a "UAF"?

> Overall the implementation does seem a bit suspicious to me. I don't really
> understand why the platform driver handles suspend/resume for the cards.
> But that may just be my lack of understanding. However, either case, I think the
> Haswell driver (sst-haswell-pcm.c) has a similar problem. I am also not sure if

It's certainly a bit unusual, usually the platform driver would just
deal with suspending itself and the card driver would handle overall
card suspension together with the core.