Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754285Ab2JCUtY (ORCPT ); Wed, 3 Oct 2012 16:49:24 -0400 Received: from smtp.outflux.net ([198.145.64.163]:55047 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753590Ab2JCUtX (ORCPT ); Wed, 3 Oct 2012 16:49:23 -0400 Date: Wed, 3 Oct 2012 13:49:19 -0700 From: Kees Cook To: "Theodore Ts'o" , Linus Torvalds , Nick Bowler , Linux Kernel Mailing List Subject: Re: Linux 3.6 Message-ID: <20121003204919.GA9092@outflux.net> References: <20121003194614.GA2893@elliptictech.com> <20121003200515.GZ9092@outflux.net> <20121003204141.GB6026@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121003204141.GB6026@thunk.org> Organization: Outflux X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1668 Lines: 38 On Wed, Oct 03, 2012 at 04:41:41PM -0400, Theodore Ts'o wrote: > On Wed, Oct 03, 2012 at 01:29:15PM -0700, Linus Torvalds wrote: > > On Wed, Oct 3, 2012 at 1:05 PM, Kees Cook wrote: > > > > > > 3.6 introduced link restrictions: > > > > Hmm. If this causes problems for others, I suspect we need to turn it > > off by default. > > > > It's a nice security thing, but considering how quickly people started > > complaining after 3.6 was out, I suspect we'll see more of these, and > > we may not have any choice. > > True, although I'm not sure we should be encouraging kernel developers > to have world-writeable directories. I suppose if it's a single-user > workstation it wouldn't matter, but you could imagine a daemon running > has "nobody" which has a stack overflow bug, and then if the user has > been careless and uses umasks so that directories in their home > directory are world writeable, well..... > > Regardless of whether or not we turn this security feature off by > default, I think it's worthwhile to look at how and why did Nick's > directories become world-writeable, and whether there is so distro > default which is causing or encouraging this. I think the benefits of this being on by default outweigh glitches like this. Based on Nick's email, it looks like a directory tree of his own creation. -Kees -- Kees Cook @outflux.net -- 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/