From owner-freebsd-jail@freebsd.org Mon Mar 14 21:42:30 2016 Return-Path: Delivered-To: freebsd-jail@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 720BBAD0356 for ; Mon, 14 Mar 2016 21:42:30 +0000 (UTC) (envelope-from jamie@freebsd.org) Received: from gritton.org (gritton.org [162.220.209.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "www.gritton.org", Issuer "StartCom Class 1 Primary Intermediate Server CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 435C9D7D; Mon, 14 Mar 2016 21:42:29 +0000 (UTC) (envelope-from jamie@freebsd.org) Received: from gritton.org (gritton.org [162.220.209.3]) by gritton.org (8.15.2/8.15.2) with ESMTPS id u2ELgN4l055350 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 14 Mar 2016 15:42:23 -0600 (MDT) (envelope-from jamie@freebsd.org) Received: (from www@localhost) by gritton.org (8.15.2/8.15.2/Submit) id u2ELgN54055349; Mon, 14 Mar 2016 15:42:23 -0600 (MDT) (envelope-from jamie@freebsd.org) X-Authentication-Warning: gritton.org: www set sender to jamie@freebsd.org using -f To: freebsd-jail@freebsd.org Subject: Re: SHM objects cannot be isolated in jails, any evolution in future FreeBSD versions? X-PHP-Originating-Script: 0:rcube.php MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 14 Mar 2016 15:42:23 -0600 From: James Gritton In-Reply-To: <1457989662.568170.549069906.791C2D05@webmail.messagingengine.com> References: <0ad738494152d249f3bbe3b722a46bd2@gritton.org> <1457989662.568170.549069906.791C2D05@webmail.messagingengine.com> Message-ID: <92e90eb23e9b15bab5066fb0667be9bd@gritton.org> X-Sender: jamie@freebsd.org User-Agent: Roundcube Webmail/1.1.2 X-BeenThere: freebsd-jail@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Discussion about FreeBSD jail\(8\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Mar 2016 21:42:30 -0000 On 2016-03-14 15:07, Mark Felder wrote: > On Sat, Mar 12, 2016, at 11:42, James Gritton wrote: >> On 2016-03-12 04:05, Simon wrote: >> > The shm_open()(2) function changed since FreeBSD 7.0: the SHM objects >> > path are now uncorrelated from the physical file system to become just >> > abstract objects. Probably due to this, the jail system do not provide >> > any form of filtering regarding shared memory created using this >> > function. Therefore: >> > >> > - Anyone can create unauthorized communication channels between jails, >> > - Users with enough privileges in any jail can access and modify any >> > SHM objects system-wide, ie. shared memory objects created in any >> > other jail and in the host system. >> > >> > I've seen a few claims that SHM objects were being handled differently >> > whether they were created inside or outside a jail. However, I tested >> > on FreeBSD 10.1 and 9.3 but found no evidence of this: both version >> > were affected by the same issue. >> > >> > A reference of such claim: >> > https://lists.freebsd.org/pipermail/freebsd-ports-bugs/2015-July/312665.html >> > >> > My initial post on FreeBSD forum discussing the issue with more >> > details: https://forums.freebsd.org/threads/55468/ >> > >> > Currently, there does not seem to be any way to prevent this. >> > >> > I'm therefore wondering if there are any concrete plans to change this >> > situation in future FreeBSD versions? Be able to block the currently >> > free inter-jail SHM-based communication seems a minimum, however such >> > setting would also most likely prevent SHM-based application to work. >> > >> > Using file based SHM objects in jails seemed a good ideas but it does >> > not seem implemented this way, I don't know why. Is this planned, or >> > are there any greater plans ongoing also involving IPC's similar >> > issue? >> >> There are no concrete plans I'm aware of, but it's definitely a thing >> that should be done. How about filing a bug report for it? You've >> already got a good write-up of the situation. >> > > Both this and SYSV IPC jail support[1] are badly needed. > > [1] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=48471 Yeah, SYSV IPC has been a need for quite a while (a good deal longer than I've been around). I'm a bit hesitant to put it in right now, since it's apparently part of upcoming vimage work. But since the Posix stuff is (virtually) path-based, it would seem a relatively simple thing to put the jail path to use in keeping those IPC objects separate. - Jamie