Re: [kernel-hardening][PATCH v4 0/3] arm: Makes ptdump resuable and add WX page checking

[Kees Cook]

On Wed, Dec 6, 2017 at 2:23 AM, Jinbum Park <jinb.park7@xxxxxxxxx> wrote:
> Hi,
>
> Page table dumping code for arm64-x86 is reusable,
> and they have function for WX page checking.
> But arm doesn't have that.
>
> This path series are to makes ptdump reusable,
> and add WX page checking for arm.
> This is heavily based on arm64 version.
>
> v2 :
> Fix a sender name of mail header, there was an mistake.
> (from "jinb.park" to Jinbum Park)
> Contents of patch-set are perfectly same.
>
> v3 :
> Take advantage of the existing pg_level and bits arrays
> to check ro, nx prot.
>
> v4 :
> Add boolean for ro_bit, nx_bit into prot_bits
> to point ro_bit, nx_bit in pg_level.
> This change is suggested by Laura Abbott.
>
> jinb.park (3):
>   arm: mm: dump: make page table dumping reusable
>   arm: mm: dump: make the page table dumping seq_file optional
>   arm: mm: dump: add checking for writable and executable pages
>
>  arch/arm/Kconfig.debug        |  33 ++++++++-
>  arch/arm/include/asm/ptdump.h |  56 ++++++++++++++++
>  arch/arm/mm/Makefile          |   3 +-
>  arch/arm/mm/dump.c            | 151 +++++++++++++++++++++++++++++-------------
>  arch/arm/mm/init.c            |   2 +
>  arch/arm/mm/ptdump_debugfs.c  |  34 ++++++++++
>  6 files changed, 232 insertions(+), 47 deletions(-)
>  create mode 100644 arch/arm/include/asm/ptdump.h
>  create mode 100644 arch/arm/mm/ptdump_debugfs.c

Please consider this series:

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

With Laura's review, this is probably ready to put into the ARM patch tracker.

-Kees

-- 
Kees Cook
Pixel Security