Maybe you're just not supposed to do this, but I've never seen a dead crash like this on a Linux system. Try this. `su` to root and type `cat /dev/port`. At least it crashed my system.
Not here, but is kinda stupid anyway. If you want port access you can use ioperm() and inb/outb, and even then you can screw your system with ease. If you believe this is a real bug and can reproduce it on the latest development kernel then you should report it to the Linux kernel mailing list.