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Subject: Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to
 /proc/slabinfo
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: kernel-hardening@lists.openwall.com,
        Andrew Morton <akpm@linux-foundation.org>,
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        Linus Torvalds <torvalds@linux-foundation.org>
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Date: Wed, 14 Sep 2011 11:24:40 -0700
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On Wed, 2011-09-14 at 19:42 +0400, Vasiliy Kulikov wrote:
> > In other words, I dunno.  If we do this in the kernel, can we at least
> > do something like CONFIG_INSECURE to both track these kinds of things
> > and make it easy to get them out of a developer's way?
> 
> What do you think about adding your user to the slabinfo's group or
> chmod it - quite the opposite Ubuntu currently does?  I think it is more
> generic (e.g. you may chmod 0444 to allow all users to get debug
> information or just 0440 and chgrp admin to allow only trusted users to
> do it) and your local policy doesn't touch the kernel.

That obviously _works_.  I'd be happy to ack your patch.  As I said,
it's pretty minimally painful, even to folks who care about slabinfo
like me.

-- Dave