Re: [PATCH v4 1/4] lib: introduce copy_struct_from_user() helper

From: Kees Cook
Date: Thu Oct 10 2019 - 12:43:30 EST


On Thu, Oct 10, 2019 at 10:40:07PM +1100, Aleksa Sarai wrote:
> Yeah, it takes about 5-10s on my laptop. We could switch it to just
> everything within a 4K block, but the main reason for testing with
> 2*PAGE_SIZE is to make sure that check_nonzero_user() works across page
> boundaries. Though we could only do check_nonzero_user() in the region
> of the page boundary (maybe i E (PAGE_SIZE-512,PAGE_SIZE+512]?)

Yeah, I like this idea: just poke at the specific edge-case.

--
Kees Cook