From owner-freebsd-stable@FreeBSD.ORG Mon Apr 3 23:46:33 2006 Return-Path: X-Original-To: freebsd-stable@FreeBSD.org Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 68B9016A41F; Mon, 3 Apr 2006 23:46:33 +0000 (UTC) (envelope-from scrappy@postgresql.org) Received: from hub.org (hub.org [200.46.204.220]) by mx1.FreeBSD.org (Postfix) with ESMTP id D6E4043D45; Mon, 3 Apr 2006 23:46:32 +0000 (GMT) (envelope-from scrappy@postgresql.org) Received: from localhost (av.hub.org [200.46.204.144]) by hub.org (Postfix) with ESMTP id CAA3A8244C3; Mon, 3 Apr 2006 20:46:27 -0300 (ADT) Received: from hub.org ([200.46.204.220]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 88817-07; Mon, 3 Apr 2006 20:46:30 -0300 (ADT) Received: from ganymede.hub.org (blk-222-82-85.eastlink.ca [24.222.82.85]) by hub.org (Postfix) with ESMTP id F418682447F; Mon, 3 Apr 2006 20:46:24 -0300 (ADT) Received: by ganymede.hub.org (Postfix, from userid 1000) id A4AED3BCC6; Mon, 3 Apr 2006 20:46:32 -0300 (ADT) Received: from localhost (localhost [127.0.0.1]) by ganymede.hub.org (Postfix) with ESMTP id A39FD3AE30; Mon, 3 Apr 2006 20:46:32 -0300 (ADT) Date: Mon, 3 Apr 2006 20:46:32 -0300 (ADT) From: "Marc G. Fournier" X-X-Sender: scrappy@ganymede.hub.org To: Stephen Frost In-Reply-To: <20060403225145.GI4474@ns.snowman.net> Message-ID: <20060403204355.T947@ganymede.hub.org> References: <26985.1144029657@sss.pgh.pa.us> <20060402231232.C947@ganymede.hub.org> <27148.1144030940@sss.pgh.pa.us> <20060402232832.M947@ganymede.hub.org> <20060402234459.Y947@ganymede.hub.org> <27417.1144033691@sss.pgh.pa.us> <20060403164139.D36756@fledge.watson.org> <14654.1144082224@sss.pgh.pa.us> <20060403194251.GF4474@ns.snowman.net> <20060403233540.D76562@fledge.watson.org> <20060403225145.GI4474@ns.snowman.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Virus-Scanned: by amavisd-new at hub.org Cc: freebsd-stable@FreeBSD.org, pgsql-hackers@postgresql.org, "Marc G. Fournier" , Robert Watson , Kris Kennaway , Tom Lane Subject: Re: [HACKERS] semaphore usage "port based"? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Apr 2006 23:46:33 -0000 On Mon, 3 Apr 2006, Stephen Frost wrote: > * Robert Watson (rwatson@FreeBSD.org) wrote: >> On Mon, 3 Apr 2006, Stephen Frost wrote: >>> This is certainly a problem with FBSD jails... Not only the >>> inconsistancy, but what happens if someone manages to get access to the >>> appropriate uid under one jail and starts sniffing or messing with the >>> semaphores or shared memory segments from other jails? If that's possible >>> then that's a rather glaring security problem... >> >> This is why it's disabled by default, and the jail documentation >> specifically advises of this possibility. Excerpt below. > > Ah, I see, glad to see it's accurately documented. Given the rather > significant use of shared memory by Postgres it seems to me that > jail'ing it under FBSD is unlikely to get you the kind of isolation > between instances that you want (the assumption being that you want to > avoid the possibility of a user under one jail impacting a user in > another jail). As such, I'd suggest finding something else if you > truely need that isolation for Postgres or dropping the jails entirely. > > Running the Postgres instances under different uids (as you'd probably > expect to do anyway if not using the jails) is probably the right > approach. Doing that and using jails would probably work, just don't > delude yourself into thinking that you're safe from a malicious user in > one jail. We don't ... we put all our databases on a central database server, even private ones, that nobody has shell access to ... we keep them isolated ... ---- Marc G. Fournier Hub.Org Networking Services (http://www.hub.org) Email: scrappy@hub.org Yahoo!: yscrappy ICQ: 7615664