>Number:         5680
>Category:       bin
>Synopsis:       Mounting and using broken mfs results into kernel panic
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    bin-bug-people (Utility Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 30 10:50:01 1998
>Last-Modified:
>Originator:     Markus Illenseer
>Organization:
	
>Release:        NetBSD 1.3.2
>Environment:
System: NetBSD lion 1.3.2 NetBSD 1.3.2 (GENERIC) #0: Sun May 24 19:45:48 EDT 1998 perry@frankenstein.piermont.com:/usr/src/sys/arch/i386/compile/GENERIC i386

Same applies to NetBSD 1.3.2 / Amiga. 

>Description:
Using mount_mfs to build a small amount of RAM results into an invalid
or broken file system which never the less be mounted. When using the
mount point afterwards, a kernel panic is caused.	
>How-To-Repeat:

# mount_mfs -s 100 swap /tmp
first cylinder group ran out of space
# mount
root device on / ffs (local, read only)
mfs:17 on /tmpo type mfs (asynchronous, local)
# cd /tmp
# ls
/tmp: bad dir ino 2 at offset 0: mangled entry
panic: bad dir
Stopped at    0xf2a0c:     unlk   a6
db>
db> trace
?(0,23e1d14,ddf2a,ddedf,f3e000) + ffffffff
?(ddedf,f3e000,23e1dc8,dd842,650900) + ffffffff
?(650900,0,dd3ec,64f580,0) + ffffffff
?(23e1e04) + ffffffff
?(23e1ea0) + ffffffff
?(23e1ea0) + ffffffff
?(648e00,23e1f88,23e1f80) + ffffffff
?(116) + ffffffff
?() + ffffffff


>Fix:
Sorry, no help here. I believe mount_mfs should not try to mount an invalid
file system.
>Audit-Trail:
>Unformatted: