It's a proprietary config file. I think it's a list of rules to forbid certain behaviours on the system. Presumably it's downloaded by some userland service, but it has to be parsed by the kernel driver. I think the files get loaded ok but the driver crashes when iterating over an array of pointers. Possibly these are the rules and some have uninitialised pointers but this is speculation based on some kernel dumps on twitter. So the bug probably existed in the kernel driver for quite a while, but they pushed a (somehow) malformed config file that triggered the crash.