On Fri, May 12, 2017 at 12:30:02PM -0700, Kees Cook wrote:

I'm clearly not explaining things well enough. I shouldn't say
"corruption", I should say "malicious manipulation". The methodology
of attacks against the stack are quite different from the other kinds
of attacks like use-after-free, heap overflow, etc. Being able to
exhaust the kernel stack (either due to deep recursion or unbounded
alloca())

I really hope we don't have alloca() use in the kernel.  Do you have
evidence to support that assertion?

IMHO alloca() (or similar) should not be present in any kernel code
because we have a limited stack - we have kmalloc() etc for that kind
of thing.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.