misc/107285: freeze and reboot by mounting twice

[Thorsten Kröger]

>Number:         107285
>Category:       misc
>Synopsis:       freeze and reboot by mounting twice
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Dec 28 16:30:15 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Thorsten Kröger
>Release:        FreeBSD 6.1-STABLE (also tested and approved on 6.2-PRERELEASE)
>Organization:
privat
>Environment:
FreeBSD work.flasupise 6.1-STABLE FreeBSD 6.1-STABLE #13: Mon Aug 21 14:00:44 CEST 2006     flas at work.flasupise:/usr/obj/usr/src/sys/FLASCONF  i386
>Description:
The problem occurred while mounting a cdrom drive two times unintended. At first i thought that wouldn't be a problem but then i unmounted the device once and tried to read on it (i made "ls") and my system freezed and then rebooted, as i had pushed the reset-button.
While using mount the normal way, i'm not having any problems.
>How-To-Repeat:
at first the relevant entrys of my fstab:
..
/dev/acd0               /cdrom          cd9660  ro,noauto       0       0
/dev/acd1               /cdrom1         cd9660  ro,noauto       0       0

here the sequens of commands i used:

#su
#mount /cdrom
#mount /cdrom
#mount
..
/dev/acd0 on /cdrom (cd9660, local, read-only)
/dev/acd0 on /cdrom (cd9660, local, read-only)
#umount /cdrom
#mount
..
/dev/acd0 on /cdrom (cd9660, local, read-only)
#ls /cdrom
--freeze and reboot--

(this also "worked" on a 6.2-PRERELEASE box)
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: