Re: [kernel-hardening] [PATCH 09/38] usercopy: Mark kmalloc caches as usercopy caches

Christoph Hellwig
2020-02-03T17:38:51Z

On Thu, Jan 30, 2020 at 11:23:38AM -0800, Kees Cook wrote:
> Hm, looks like it's allocated from the low 16MB. Seems like poor naming!
> :) There seems to be a LOT of stuff using GFP_DMA, and it seems unlikely
> those are all expecting low addresses?

Most of that is either completely or partially bogus. Besides the
weird S/390 stuff pretty much everything should be using the dma
allocators. A couple really messed up drivers even pass GFP_DMA*
to the dma allocator, but my patches to fix that up seem to be stuck.