Re: [PATCH v6 0/3] security: Yama LSM

From: Kees Cook
Date: Fri Nov 18 2011 - 17:44:45 EST


On Fri, Nov 18, 2011 at 1:45 PM, Roland McGrath <roland@xxxxxxxxxxxxx> wrote:
>> Do you have any objection to my LSM performing ptrace restrictions?
>> It's entirely self-contained, and all the major upstream crash
>> handlers are already using the prctl() interface it uses to declare
>> ptrace attach relationships.
>
> I don't have the context of what your LSM does.  But other LSMs apply their
> own rules in security_ptrace().  That's what the hook is for.  I'm not sure
> why we would object from the perspective of core ptrace functionality.
> LSMs are LSMs.  Their behavior is between you and your users, as far as I
> am concerned.  As experts on ptrace and aficionados of its users, we may
> have thoughts on what constraints on ptrace users would find annoying.
> But that doesn't mean we'd object per se to whatever bizarre constraints
> users want to ask an LSM to put on them.

Yup, that's precisely what Yama does as well. Sounds like you're not
naking an LSM that uses security_ptrace(), then.

Thanks!

-Kees

--
Kees Cook
ChromeOS Security
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