Re: [PATCH] dma-mapping: Lift address space checks out of debug code

From: Kees Cook
Date: Wed Oct 02 2019 - 20:03:14 EST


On Wed, Oct 02, 2019 at 04:58:39PM -0700, Kees Cook wrote:
> In the USB case, it'll actually refuse to do the operation. Should
> dma_map_single() similarly fail? I could push these checks down into
> dma_map_single(), which would be a no-change on behavior for USB and
> gain the checks on all other callers...

Which begs the question: are all callers actually checking the result of
dma_map_single(). Many are paired with dma_mapping_error(), but lots
more aren't...

--
Kees Cook