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Date: Thu, 9 Feb 2012 13:35:04 +0400
From: Vasiliy Kulikov <segoon@openwall.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>, Steven Rostedt <rostedt@goodmis.org>,
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Subject: Re: [PATCH v3 4/4] Allow unprivileged chroot when safe
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On Mon, Jan 30, 2012 at 14:51 -0800, Andy Lutomirski wrote:
> That's neat!  CLONE_NEWPID might be safe with no_new_privs, too.
> Unprivileged CLONE_NEWPID would also be a nice, straightforward way to
> start up a process hierarchy and then reliably kill the whole thing
> when you're done with it.

It worth checking whether creating HUGE number or pid namespaces is
able to lock down the system for a significant period of time.  E.g.
triggering thousands of pid_ns enumeration under a spinlock.

The same with every "enable this privileged feature to unprivileged
users under certain circumstances" step.

Thanks,

-- 
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments