From owner-freebsd-current Thu Apr 4 23:35:47 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id XAA00984 for current-outgoing; Thu, 4 Apr 1996 23:35:47 -0800 (PST) Received: from gw.pinewood.nl (gw.pinewood.nl [192.31.139.9]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id XAA00979 for ; Thu, 4 Apr 1996 23:35:44 -0800 (PST) Received: (from smap@localhost) by gw.pinewood.nl (8.6.12/8.6.12) id JAA12889; Fri, 5 Apr 1996 09:35:38 +0200 Received: from pwood1.pinewood.nl(192.168.1.10) by gw.pinewood.nl via smap (V1.3) id sma012887; Fri Apr 5 09:35:27 1996 Received: (from franky@localhost) by pwood1.pinewood.nl (8.7.3/8.6.12) id JAA09065; Fri, 5 Apr 1996 09:35:26 +0200 (DST) From: "Frank ten Wolde" Message-Id: <9604050935.ZM9063@pwood1.pinewood.nl> Date: Fri, 5 Apr 1996 09:35:25 +0000 In-Reply-To: Terry Lambert "Re: 2.2-960323 Panic in mount_msdos" (Apr 4, 13:10) References: <199604042010.NAA22425@phaeton.artisoft.com> X-Face: 'BsFf8'k.q?J#?|$D*,)/?sRB{woUK&9\5K{ERmT;VTSyNLBb?muLf>b:Pt&VTDw8YCaC]6 C!MRSMr5UNjZLa]fi? X-Mailer: Z-Mail (3.2.1 10oct95) To: Terry Lambert Subject: Re: 2.2-960323 Panic in mount_msdos Cc: freebsd-current@FreeBSD.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-current@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk Hi, > > I just tried to mount a Windows NT file system (NTFS) using: > > > > mount -t msdos /dev/sd0s2 /dos > > > > (I thought it was an MSDOS-FAT file system :-). The 2.2-960223-SNAPSHOT > > of FreeBSD immediately paniced: > > [ ... ] > > > I know you cannot mount an NTFS under FreeBSD, but at least the system > > should not crash. > > > > I just report this problem as I have too little knowledge of the internals > > of the kernel to fix the problem myself :-) > > A file system operates by copying on disk strucutures into memory > and then using the offsets in the coppy to access additional memory. > > It does not bounds-check these accesses. Yep, I found out :-) > Not bounds-checking dereferences isn't an error; it an optimization, > and it's allowable because mount is not a user accessable command > (you have to be root). I slightly disagree. Even as root I could make a typo and by mistake specifiy the wrong partition/slice to mount, causing the entire system to die. It would have been nice if some sanity checking would have been performed, so that the kernel simply would abort the mount(2) system call with an appropriate error (wrong FS type, or something similar). [...] > The DOSFS is being rewritten (not by me). Neither by me. Don't get me wrong, I *really* like FreeBSD and my remarks are not ment to critisize anyone. I, for sure, do *not* have the time and resources to contribute significantly to FreeBSD and I certainly do not make demands of any kind :-) I simply pointed out the panic. Maybe the code maintainer of the DOSFS can use this info to make the system even more stable. -Frank -- ---------------------------------------------------------------------- F.W. ten Wolde (PA3FMT) Pinewood Automation B.V. E-mail: franky@pinewood.nl Kluyverweg 2a Phone: +31-15 2682543 2629 HT Delft