> RedoxFS (file system) – inspired by the ZFS file system
It doesn't seem necessary to write either one of these if you just want a Rust kernel.
For one thing, secure malloc replacements are not very useful because the main customer that needs them, web browsers, will ignore yours because it's "too slow" and continue using their own. (Also, unless you're testing on an MTE/CHERI system your assumptions about what makes one secure are probably incorrect.)
The point of this work isn't "just a kernel in Rust." The point is to help the millions/billions/zillions of Linux deployments get better. A different kernel is a different goal.