Subject: kern/9034: can write to a mounted ro msdos disk
To: None <gnats-bugs@gnats.netbsd.org>
From: Shane Hutchison <shutchis@amarok.eyring.com>
List: netbsd-bugs
Date: 12/20/1999 11:48:39
>Number: 9034
>Category: kern
>Synopsis: can write to a mounted ro msdos disk
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: kern-bug-people (Kernel Bug People)
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Mon Dec 20 11:48:01 1999
>Last-Modified:
>Originator: Shane Hutchison
>Organization:
>Release: NetBSD-1.4.1
>Environment:
i386, NetBSD,
System: NetBSD amarok.eyring.com 1.4.1 NetBSD 1.4.1 (AMAROK) #1: Mon Dec 13 12:08:25 MST 1999 root@amarok.eyring.com:/usr/src/sys/arch/i386/compile/AMAROK i386
>Description:
- quoted material -
amarok-~/pdos/4/binaries/special/floppy$ tar -czf 3580-264.tar.tz *
amarok-~/pdos/4/binaries/special/floppy$ ls
3580-2~1.tz fbiosw.sr fparm.sr mibiosu.sr readme
f32parm.sr ffrmt.sr mfrmt.sr miparm.sr wfc1.sr
amarok-~/pdos/4/binaries/special$ mount
/dev/wd0a on / type ffs (local)
/dev/wd0e on /usr type ffs (local)
/dev/wd0f on /var type ffs (local)
/dev/wd0g on /tmp type ffs (local)
kernfs on /kern type kernfs (local)
/dev/fd0a on /usr/home/shutchis/pdos/4/binaries/special/floppy type msdos (local, nodev, nosuid, read-only, mounted by shutchis)
- submitters' notes -
When mistakenly denoting the wrong location to create the above mentioned 3580-264.tar.gz (written as .tar.tz), the file was created on the mounted HD floppy which was mounted only as read-only. Worthy of note is that the file created (besides ofcourse being a lfn, had 0 bytes of information - thus the filename was written to the otherwise read-only disk but no actual information was written.
>How-To-Repeat:
amarokbash-2.03# mount -t msdos -o ro /dev/fd0a /mnt
amarokbash-2.03# echo something > /mnt/file
amarokbash-2.03# ls /mnt
file
amarokbash-2.03# ll /mnt
total 1
-rwxr-xr-x 1 root wheel 10 Dec 20 12:29 file
amarokbash-2.03# umount /mnt
(note: when checking floppy on MSDOS computer "file" showed as zero (0) bytes)
>Fix:
>Audit-Trail:
>Unformatted: