From owner-freebsd-stable@FreeBSD.ORG Wed Nov 12 08:58:27 2003 Return-Path: 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 E7A4216A4CE for ; Wed, 12 Nov 2003 08:58:27 -0800 (PST) Received: from lurza.secnetix.de (lurza.secnetix.de [195.143.231.20]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8393B43FE0 for ; Wed, 12 Nov 2003 08:58:26 -0800 (PST) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (felopi@localhost [127.0.0.1]) by lurza.secnetix.de (8.12.9p2/8.12.9) with ESMTP id hACGwPb0045424 for ; Wed, 12 Nov 2003 17:58:25 +0100 (CET) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.12.9p2/8.12.9/Submit) id hACGwPVJ045423; Wed, 12 Nov 2003 17:58:25 +0100 (CET) (envelope-from olli) Date: Wed, 12 Nov 2003 17:58:25 +0100 (CET) Message-Id: <200311121658.hACGwPVJ045423@lurza.secnetix.de> From: Oliver Fromme To: freebsd-stable@FreeBSD.ORG In-Reply-To: <20031111164512.P56037@ganymede.hub.org> X-Newsgroups: list.freebsd-stable User-Agent: tin/1.5.4-20000523 ("1959") (UNIX) (FreeBSD/4.9-RELEASE (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Subject: Re: kernel panic on jailed sshd - 4.9-release X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: freebsd-stable@FreeBSD.ORG List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Nov 2003 16:58:28 -0000 Marc G. Fournier wrote: > On Tue, 11 Nov 2003, Oliver Fromme wrote: > > Kovács János wrote: > > > Just installed 4.9-RELEASE with jailed sshd over a null-mounted (bin, > > > dev,etc,usr) > > > dirs crashing. > > > > It's well-known that NULLFS (as well as UNIONFS) are unstable > > in FreeBSD 4.x and can cause crashes. > > God, I so hate answers like this ... its the "I'm too lazy to care" > answer ... If I had been lazy, I wouldn't have written an answer at all. In most cases when machines crash and NULLFS is in use, the latter is causing it. > ... and it doesn't even come close to addressing the problem, and that is > that in 4.8, he didn't have this problem, while in 4.9, he does ... Possibly a program which now triggers a NULLFS problem. For example, it might be that some program in 4.8 used standard read/write to access files, and it was changed to use mmap() in 4.9, which can be a problem with NULLFS. Of course I could be wrong. Something else could have caused that particular crash. But still it is a good idea not to use NULLFS if possible. (Particularly in a jail environment if you don't have strict control over which programs get executed, such as a user shell box.) If a miracle happened and NULLFS got stable recently, then the mount_null(8) manpage should be fixed, because it states just the opposite. ;-) Regards Oliver -- Oliver Fromme, secnetix GmbH & Co KG, Oettingenstr. 2, 80538 München Any opinions expressed in this message may be personal to the author and may not necessarily reflect the opinions of secnetix in any way. We're sysadmins. To us, data is a protocol-overhead.