Re: [PATCH v2 11/11] mm: SLUB hardened usercopy support

From: Balbir Singh
Date: Thu Jul 14 2016 - 22:06:31 EST


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.

Balbir Singh.