Bug in IO bitmap handling? Probably exploitable (2.6.5)

Hello. The attached is the small program that tries to write 0x20 to port 0x20. Normally this should cause SIGSEGV, so the program should crash. I think there is a bug in the 2.6 kernels though, which makes it to not crash if some trivial conditions are met. Basically it seems that if any process...