Randomizing structure layout

> When potential attackers do not know the layout of a structure, it becomes much harder for them to overwrite specific fields in those structures. Thus, the barrier to exploitation is raised significantly

There are 6 possible permutations for structures with 3 fields, 24 permutations for structures with 4 fields, and so one. With millions (billions?) of installed kernel binaries, this still leaves a good number of systems for each variant. And if the attacker knows distribution and version number, the structure layout is trivial to find out.