> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=c65c1877bd6826ce0d9713d76e30a7bed8e49f38

I think the assert is just bogus at least in the early case.
early_kmem_cache_node_alloc() says:
 * No kmalloc_node yet so do it by hand. We know that this is the first
 * slab on the node for this slabcache. There are no concurrent accesses
 * possible.

Should we do something like the attached patch?  (very lightly tested)