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From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman)
To: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Cc: Linux Containers
	<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
	Sebastian Krahmer <krahmer-l3A5Bk7waGM@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: CLONE_NEWUSER|CLONE_FS root exploit
Date: Wed, 13 Mar 2013 11:35:15 -0700	[thread overview]
Message-ID: <87r4jjkv18.fsf@xmission.com> (raw)
In-Reply-To: <20130313175729.GH12501-oSa+0FWJbaXR7s880joybQ@public.gmane.org> (Kees Cook's message of "Wed, 13 Mar 2013 10:57:29 -0700")

Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> writes:

> Hi,
>
> It seem like we should block (at least) this combination. On 3.9, this
> exploit works once uidmapping is added.
>
> http://www.openwall.com/lists/oss-security/2013/03/13/10

Yes.  That is a bad combination.  It let's chroot confuse privileged
processes.

Now to figure out if this is easier to squash by adding a user_namespace
to fs_struct or by just forbidding this combination.

Eric

       reply	other threads:[~2013-03-13 18:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20130313175729.GH12501@outflux.net>
     [not found] ` <20130313175729.GH12501-oSa+0FWJbaXR7s880joybQ@public.gmane.org>
2013-03-13 18:35   ` Eric W. Biederman [this message]
     [not found]     ` <87r4jjkv18.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2013-03-14  1:48       ` CLONE_NEWUSER|CLONE_FS root exploit Andy Lutomirski
     [not found]         ` <51412C67.30908-3s7WtUTddSA@public.gmane.org>
2013-03-14 20:29           ` Eric W. Biederman
     [not found]             ` <87hakdrai1.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2013-03-14 21:32               ` Andy Lutomirski

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