Re: [PATCH v6] powerpc: Do not make the entire heap executable

From: Kees Cook
Date: Tue Oct 04 2016 - 12:54:22 EST

On Mon, Oct 3, 2016 at 5:18 PM, Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
> Kees Cook <keescook@xxxxxxxxxxxx> writes:
>> On Mon, Oct 3, 2016 at 9:13 AM, Denys Vlasenko <dvlasenk@xxxxxxxxxx> wrote:
>>> On 32-bit powerpc the ELF PLT sections of binaries (built with --bss-plt,
>>> or with a toolchain which defaults to it) look like this:
> ...
>>> Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
>>> Signed-off-by: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
>>> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
>>> Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
>>> CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
>>> CC: Paul Mackerras <paulus@xxxxxxxxx>
>>> CC: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
>>> CC: Kees Cook <keescook@xxxxxxxxxxxx>
>>> CC: Oleg Nesterov <oleg@xxxxxxxxxx>
>>> CC: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
>>> CC: Florian Weimer <fweimer@xxxxxxxxxx>
>>> CC: linux-mm@xxxxxxxxx
>>> CC: linuxppc-dev@xxxxxxxxxxxxxxxx
>>> CC: linux-kernel@xxxxxxxxxxxxxxx
>>> ---
>>> Changes since v5:
>>> * made do_brk_flags() error out if any bits other than VM_EXEC are set.
>>> (Kees Cook: "With this, I'd be happy to Ack.")
>>> See
>> Excellent, thanks for the v6! Should this go via the ppc tree or the -mm tree?
> -mm would be best, given the diffstat I think it's less likely to
> conflict if it goes via -mm.

Okay, excellent. Andrew, do you have this already in email? I think
you weren't on the explicit CC from the v6...


Kees Cook
Nexus Security