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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Jann Horn <jannh@google.com>
Cc: Laurent Vivier <laurent@vivier.eu>,
	kernel list <linux-kernel@vger.kernel.org>,
	Linux API <linux-api@vger.kernel.org>,
	containers@lists.linux-foundation.org, dima@arista.com,
	Al Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace
Date: Thu, 01 Nov 2018 07:10:13 -0700	[thread overview]
Message-ID: <1541081413.2853.6.camel@HansenPartnership.com> (raw)
In-Reply-To: <CAG48ez3HnkRM6bUZMNjuTy5DgujgamEKhZOEWDfCjqW7fTJSzQ@mail.gmail.com>

On Thu, 2018-11-01 at 04:51 +0100, Jann Horn wrote:
> On Thu, Nov 1, 2018 at 3:59 AM James Bottomley
> <James.Bottomley@hansenpartnership.com> wrote:
> > 
> > On Tue, 2018-10-16 at 11:52 +0200, Laurent Vivier wrote:
> > > Hi,
> > > 
> > > Any comment on this last version?
> > > 
> > > Any chance to be merged?
> > 
> > I've got a use case for this:  I went to one of the Graphene talks
> > in Edinburgh and it struck me that we seem to keep reinventing the
> > type of sandboxing that qemu-user already does.  However if you
> > want to do an x86 on x86 sandbox, you can't currently use the
> > binfmt_misc mechanism because that has you running *every* binary
> > on the system emulated. Doing it per user namespace fixes this
> > problem and allows us to at least cut down on all the pointless
> > duplication.
> 
> Waaaaaait. What? qemu-user does not do "sandboxing". qemu-user makes
> your code slower and *LESS* secure. As far as I know, qemu-user is
> only intended for purposes like development and testing.

Sandboxing is about protecting the cloud service provider (and other
tenants) from horizontal attack by reducing calls to the shared kernel.
 I think it's pretty indisputable that full emulation is an effective
sandbox in that regard.

We can argue for about bugginess vs completeness, but technologically
qemu-user already has most of the system calls, which seems to be a
significant problem with other sandboxes.  I also can't dispute it's
slower, but that's a tradeoff for people to make.

James


  parent reply	other threads:[~2018-11-01 14:10 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10 16:14 Laurent Vivier
2018-10-10 16:14 ` [PATCH v6 1/1] ns: add binfmt_misc to the user namespace Laurent Vivier
2018-10-16 10:13   ` Rasmus Villemoes
2018-10-16 10:53     ` Laurent Vivier
2018-10-16 16:22   ` Andrei Vagin
2018-10-24 17:15     ` Laurent Vivier
2018-10-30  8:51       ` Laurent Vivier
2018-11-06 19:40         ` Jann Horn
2018-10-16  9:52 ` [PATCH v6 0/1] ns: introduce binfmt_misc namespace Laurent Vivier
2018-11-01  2:59   ` James Bottomley
2018-11-01  3:51     ` Jann Horn
2018-11-01 12:28       ` Laurent Vivier
2018-11-01 14:16         ` Eric W. Biederman
2018-11-29 13:05           ` Laurent Vivier
2018-12-29 15:41             ` Laurent Vivier
2018-11-01 14:10       ` James Bottomley [this message]
2018-11-01 14:44         ` Jann Horn

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