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
WARNING: multiple messages have this Message-ID (diff)
From: ebiederm@xmission.com (Eric W. Biederman)
To: Kees Cook <keescook@chromium.org>
Cc: Sebastian Krahmer <krahmer@suse.de>,
linux-kernel@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
Linux Containers <containers@lists.linux-foundation.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@outflux.net> (Kees Cook's message of "Wed, 13 Mar 2013 10:57:29 -0700")
Kees Cook <keescook@chromium.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
next prev parent reply other threads:[~2013-03-13 18:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-13 17:57 CLONE_NEWUSER|CLONE_FS root exploit Kees Cook
[not found] ` <20130313175729.GH12501-oSa+0FWJbaXR7s880joybQ@public.gmane.org>
2013-03-13 18:35 ` Eric W. Biederman [this message]
2013-03-13 18:35 ` Eric W. Biederman
[not found] ` <87r4jjkv18.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2013-03-14 1:48 ` Andy Lutomirski
2013-03-14 1:48 ` Andy Lutomirski
[not found] ` <51412C67.30908-3s7WtUTddSA@public.gmane.org>
2013-03-14 20:29 ` Eric W. Biederman
2013-03-14 20:29 ` Eric W. Biederman
[not found] ` <87hakdrai1.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2013-03-14 21:32 ` Andy Lutomirski
2013-03-14 21:32 ` Andy Lutomirski
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