According to this breakdown: https://ghloc.vercel.app/Poseidon-fan/linux-0.11-rs?branch=m...

It's about 15k lines of code for the kernel and the rest is various utilities, libraries and programs that can run on the kernel.

Also, after a quick look at a few files, the rust version appears to be much more commented. Not sure if that makes up the extra several thousand lines, but surely counts accounts for some of that.