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