Bug 51

Accesses to certain files on an NFS mounted file system make the system
panic with a page fault in kernel mode. The file system is accessed through 
an AFS-NFS translator, AFS accesses from other systems work, NFS accesses 
from a SunOS 4.1.3 system hang, but can be interrupted.
(There seems to be something wrong with that file system, accesses to files 
owned by one particular UID fail. But user mode accesses shouldn't crash 
the kernel ...)

Panic messages:

Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x28
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xf0123eb2
code segment		= base rx0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 877 (tar)
interrupt mask		= 
panic: page fault

Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x28
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xf0123eb2
code segment		= base rx0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 152 (tar)
interrupt mask		= 
panic: page fault

Fix: 

None I know of ...
How-To-Repeat: 
mount rs2.rrz.uni-koeln.de:/afs/rrz/pub /ftp
cat /ftp/tex/graphics/bm2font/*

(Please don't NFS mount that file system, except for testing ...)

The instruction pointer indicates a problem in vn_open(), it starts
at 0xf0123aac and ends before 0xf0123f30 in my /kernel ...