From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65997C6786F for ; Thu, 1 Nov 2018 14:10:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 266F620831 for ; Thu, 1 Nov 2018 14:10:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="rS37x5nr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 266F620831 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728498AbeKAXNW (ORCPT ); Thu, 1 Nov 2018 19:13:22 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:50716 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728192AbeKAXNW (ORCPT ); Thu, 1 Nov 2018 19:13:22 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 900AA8EE179; Thu, 1 Nov 2018 07:10:14 -0700 (PDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Q8slHTOrFVx4; Thu, 1 Nov 2018 07:10:14 -0700 (PDT) Received: from [153.66.254.194] (unknown [50.35.68.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id E1D8B8EE0BA; Thu, 1 Nov 2018 07:10:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1541081414; bh=eBWW4hk4Zuj7T2PXmMtao8skRRHjYw5FMkF5Zp100pA=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=rS37x5nrxDc8CrbFHv7FiLXhU6BQpqa4MWrtkldNljBc7HPIrYtOVfv8HXvo6Plfh /LpAbnAuDnaNxM/c4OWlubW/f83jNEFgqIGKB4Ouw0y0XooDJXF/xVD5q0M7yrrhvS /zGP3CKrgXQaJi/UKMY+N0Gs+uj8mb31qL3PBhvQ= Message-ID: <1541081413.2853.6.camel@HansenPartnership.com> Subject: Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace From: James Bottomley To: Jann Horn Cc: Laurent Vivier , kernel list , Linux API , containers@lists.linux-foundation.org, dima@arista.com, Al Viro , linux-fsdevel@vger.kernel.org, "Eric W. Biederman" Date: Thu, 01 Nov 2018 07:10:13 -0700 In-Reply-To: References: <20181010161430.11633-1-laurent@vivier.eu> <7ed6f823-547b-922d-59ff-aba9c4c3ab39@vivier.eu> <1541041159.4632.6.camel@HansenPartnership.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-11-01 at 04:51 +0100, Jann Horn wrote: > On Thu, Nov 1, 2018 at 3:59 AM James Bottomley > 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