A git bisect reveals it to be fixed by this commit: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f7a59018953910032231c0a019208c4b0a4a8bc3
> maple_tree: make mas_erase() more robust > > mas_erase() may not deal correctly with all maple states. Make the > function more robust by ensuring the state is in one of the two acceptable > states.
