Panic when trying to mount cd9660 as udf

By accident, I tried to mount a CD as UDF, and got the follwoing panic:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x0
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc06c2f6c
stack pointer           = 0x10:0xcda4bac0
frame pointer           = 0x10:0xcda4bacc
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 530 (mount_udf)

This seems to be easily reproducable. First I got it on my workstation
running 5.2-BETA, and I then reproduced it on my test machine which runs
-CURRENT from 4 days ago:

FreeBSD cardassian.borderworlds.dk 5.1-CURRENT FreeBSD 5.1-CURRENT #0: Wed Nov 19 04:22:32 CET 2003     root_at_cardassian.borderworlds.dk:/usr/obj/usr/src/sys/GENERIC  i386

The output in this mail is from the test machine.

This is the backtrace I got from the resulting crashdump:

#0  doadump () at /usr/src/sys/kern/kern_shutdown.c:240
#1  0xc066d6fb in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:372
#2  0xc066dafd in panic () at /usr/src/sys/kern/kern_shutdown.c:550
#3  0xc048ac32 in db_panic () at /usr/src/sys/ddb/db_command.c:450
#4  0xc048ab92 in db_command (last_cmdp=0xc0938360, cmd_table=0xc08c3c00, 
    aux_cmd_tablep=0xc08baa04, aux_cmd_tablep_end=0xc08baa1c)
    at /usr/src/sys/ddb/db_command.c:346
#5  0xc048acd5 in db_command_loop () at /usr/src/sys/ddb/db_command.c:472
#6  0xc048dcd5 in db_trap (type=12, code=0) at /usr/src/sys/ddb/db_trap.c:73
#7  0xc0812dcc in kdb_trap (type=12, code=0, regs=0xcda4ba80)
    at /usr/src/sys/i386/i386/db_interface.c:171
#8  0xc08294d6 in trap_fatal (frame=0xcda4ba80, eva=0)
    at /usr/src/sys/i386/i386/trap.c:816
#9  0xc0829182 in trap_pfault (frame=0xcda4ba80, usermode=0, eva=0)
    at /usr/src/sys/i386/i386/trap.c:735
#10 0xc0828d23 in trap (frame=
      {tf_fs = 24, tf_es = 16, tf_ds = 16, tf_edi = -1040053552, tf_esi = 1, tf_ebp = -844842292, tf_isp = -844842324, tf_ebx = 0, tf_edx = 4, tf_ecx = 1, tf_eax = 0, tf_trapno = 12, tf_err = 0, tf_eip = -1066651796, tf_cs = 8, tf_eflags = 66182, tf_esp = 6, tf_ss = 0}) at /usr/src/sys/i386/i386/trap.c:420
#11 0xc0814818 in calltrap () at {standard input}:94
#12 0xc06c3913 in vfs_mount_destroy (mp=0x0, td=0x0)
    at /usr/src/sys/kern/vfs_mount.c:537
#13 0xc06c472f in vfs_domount (td=0xc20c7dc0, fstype=0xc2020ad0 "udf", 
    fspath=0xc2020ab0 "/mnt", fsflags=1, fsdata=0xc2020c00, compat=0)
    at /usr/src/sys/kern/vfs_mount.c:938
#14 0xc06c3a39 in vfs_nmount (td=0x0, fsflags=0, fsoptions=0x0)
    at /usr/src/sys/kern/vfs_mount.c:581
#15 0xc06c353d in nmount (td=0x0, uap=0xcda4bd10)
    at /usr/src/sys/kern/vfs_mount.c:407
#16 0xc0829870 in syscall (frame=
      {tf_fs = 47, tf_es = 47, tf_ds = 47, tf_edi = -1077940702, tf_esi = 8, tf_ebp = -1077940972, tf_isp = -844841612, tf_ebx = 5, tf_edx = -1077940736, tf_ecx = 10, tf_eax = 378, tf_trapno = 12, tf_err = 2, tf_eip = 671876783, tf_cs = 31, tf_eflags = 582, tf_esp = -1077942196, tf_ss = 47})
    at /usr/src/sys/i386/i386/trap.c:1010
#17 0xc081486d in Xint0x80_syscall () at {standard input}:136

-- 
Best regards
    Christian Laursen