Messages in this thread | | | Date | Tue, 2 Oct 2012 13:34:06 -0700 | Subject | Re: [PATCH] hardening: add PROT_FINAL prot flag to mmap/mprotect | From | Kees Cook <> |
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Hi,
On Mon, Aug 20, 2012 at 2:48 PM, Ard Biesheuvel <ard.biesheuvel@gmail.com> wrote: >> This seems like a good idea to me. It would allow more than just the >> loader to harden userspace allocations. It's a more direct version of >> PaX's "MPROTECT" feature[1]. That feature hardens existing loaders, >> but doesn't play nice with JITs (like Java), but this lets a loader >> (or JIT) opt-in to the protection and have some direct control over it. > > 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?
>> 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?
-Kees
-- Kees Cook Chrome OS Security
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