tmpfs: fix use-after-free of mempolicy object from https://github.com/faux123/tuna/commit/a95f23a87f048318db586d087725b574f40002ce
mm: fix pageblock bitmap allocation from https://github.com/faux123/tuna/commit/744dac7d299be82e4d13b217e81eb4bfee9826a8