Busybox in rust and it will give more stable and memory safety in firmware and making openwrt a most secure router firmware available. And 70%of all vulnerabilities happens due to memory related issues.
Now rust has been added in linux kernel. What are the thoughts on this.
None of the busybox networking utilities used by OpenWrt (ntpd, udhcpc) are implemented there, so it's a non-starter. Improved security for local core utilities might be a nice addition on paper, but with OpenWrt being a mostly single-user system with most things running as root, hardening against potential local exploits that would lead to privilege escalation would not significantly improve overall security.
Apart from that rust does not support all CPU architectures supported by OpenWrt.
There's already a number of other re-writes of BusyBox in various forms (ToyBox is one such).
There's nothing particularly 'special' about a Rust version. Rust is not magic. And it's not magically 'memory safe' either. In fact there's an entire facet of Rust that is dedicated to 'unsafe' operations https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html
When writing low level interfaces, a large volume of that work will require 'unsafe' mechanisms and hence not be 'memory safe' by virtue.
If the Rust version can get to a similar functionality level, and similar size, then it might be useful. But I think OpenWRT has enough other challenges, there's not much interest in also taking on board the development of another such BusyBox replacement.