Messages in this thread | | | Date | Tue, 2 Oct 2012 15:10:56 -0700 | Subject | Re: [PATCH] hardening: add PROT_FINAL prot flag to mmap/mprotect | From | Kees Cook <> |
| |
On Tue, Oct 2, 2012 at 2:41 PM, Ard Biesheuvel <ard.biesheuvel@gmail.com> wrote: > 2012/10/2 Kees Cook <keescook@chromium.org>: >>> If desired, additional restrictions can be imposed by using the >>> security framework, e.g,, disallow non-final r-x mappings. >> >> Interesting; what kind of interface did you have in mind? > > The 'interface' we use is a LSM .ko which registers handlers for > mmap() and mprotect() that fail the respective invocations if the > passed arguments do not adhere to the policy.
Seems reasonable.
>>>> It seems like there needs to be a sensible way to detect that this flag is >>>> available, though. >>> >>> I am open for suggestions to address this. Our particular >>> implementation of the loader (on an embedded system) tries to set it >>> on the first mmap invocation, and stops trying if it fails. Not the >>> most elegant approach, I know ... >> >> Actually, that seems easiest. >> >> Has there been any more progress on this patch over-all? > > No progress.
Al, Andrew, anyone? Thoughts on this? (First email is https://lkml.org/lkml/2012/8/14/448)
-Kees
-- Kees Cook Chrome OS Security
| |