Re: [PATCH v2 11/11] mm: SLUB hardened usercopy support
From: Kees Cook
Date: Fri Jul 15 2016 - 00:29:34 EST
On Thu, Jul 14, 2016 at 7:05 PM, Balbir Singh <bsingharora@xxxxxxxxx> wrote:
> On Wed, Jul 13, 2016 at 02:56:04PM -0700, Kees Cook wrote:
>> Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the
>> SLUB allocator to catch any copies that may span objects. Includes a
>> redzone handling fix from Michael Ellerman.
>> Based on code from PaX and grsecurity.
>> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>> init/Kconfig | 1 +
>> mm/slub.c | 36 ++++++++++++++++++++++++++++++++++++
>> 2 files changed, 37 insertions(+)
>> diff --git a/init/Kconfig b/init/Kconfig
>> index 798c2020ee7c..1c4711819dfd 100644
>> --- a/init/Kconfig
>> +++ b/init/Kconfig
>> @@ -1765,6 +1765,7 @@ config SLAB
>> config SLUB
>> bool "SLUB (Unqueued Allocator)"
>> + select HAVE_HARDENED_USERCOPY_ALLOCATOR
> Should this patch come in earlier from a build perspective? I think
> patch 1 introduces and uses __check_heap_object.
__check_heap_object in patch 1 is protected by a check for
It seemed better to be to do arch enablement first, and then add the
per-allocator heap object size check since it was a distinct piece.
I'm happy to rearrange things, though, if there's a good reason.
Chrome OS & Brillo Security