Re: [PATCH] ppp: mppe: Remove VLA usage

From: Paul Mackerras
Date: Thu Aug 02 2018 - 23:13:26 EST


On Thu, Aug 02, 2018 at 04:27:01PM -0700, Kees Cook wrote:
> On Mon, Jul 16, 2018 at 4:01 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > On Mon, Jul 16, 2018 at 6:05 AM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >> In the quest to remove all stack VLA usage from the kernel[1], this
> >> removes the discouraged use of AHASH_REQUEST_ON_STACK (and associated
> >> VLA) by switching to shash directly and keeping the associated descriptor
> >> allocated with the regular state on the heap.
> >>
> >> [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx
> >>
> >> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> >
> > I had concerns at first that this approach might make it slower, but
> > upon reading through implementation of the shash_ahash_ implementation,
> > I concluded that it can only be better than before, improving both
> > performance and stack usage.
> >
> > Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> Paul,
>
> Is this something you can take via your tree?

No, it would go via the netdev tree, I expect.

Paul.