Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754482AbaLHWbb (ORCPT ); Mon, 8 Dec 2014 17:31:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57982 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbaLHWb3 (ORCPT ); Mon, 8 Dec 2014 17:31:29 -0500 Date: Mon, 8 Dec 2014 17:31:11 -0500 From: Dave Jones To: Linus Torvalds Cc: "Theodore Ts'o" , "Kirill A. Shutemov" , Al Viro , Linux Kernel Mailing List , linux-fsdevel , Network Development Subject: Re: [RFC][PATCHES] iov_iter.c rewrite Message-ID: <20141208223111.GA17949@redhat.com> Mail-Followup-To: Dave Jones , Linus Torvalds , Theodore Ts'o , "Kirill A. Shutemov" , Al Viro , Linux Kernel Mailing List , linux-fsdevel , Network Development References: <20141204202011.GO29748@ZenIV.linux.org.uk> <20141208164650.GB29028@node.dhcp.inet.fi> <20141208175805.GB22149@ZenIV.linux.org.uk> <20141208185635.GA25867@node.dhcp.inet.fi> <20141208192358.GB25867@node.dhcp.inet.fi> <20141208221401.GA4991@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 08, 2014 at 02:23:06PM -0800, Linus Torvalds wrote: > On Mon, Dec 8, 2014 at 2:14 PM, Theodore Ts'o wrote: > > > > running trinity as root should be quite safe in a VM. :-) > > It's not so much the safety that I'd worry about, it's the "you can > legitimately just reboot it or cause kernel corruption as root". You > may not cause any problems outside of the VM, but any oopses inside > the VM might be due to trinity just doing bad things as root, rather > than kernel bugs.. > > Of course, it's probably hard to hit things like laoding random > modules etc, since even without signature requirements there are tons > of ELF sanity checks and other things. So it might be hard to actually > do those kinds of "corrupt kernel memory as root" things with trinity. It also goes out of its way to avoid doing obviously stupid things, like using /dev/mem as an fd, plus a whole bunch of similar sysfs/procfs knobs. There are still likely a whole bunch of similar things that might have horrible effects too. It's been on my todo for a while to revisit that particular case and blacklist a bunch of other things. And then there's obviously "don't do this syscall, ever" or "with these args" type things, which could use expanding.. It's a big effort tbh. I'm amazed that Sasha, Kirill and everyone else running it as root in vm's aren't buried alive in false-positives. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/