Exploiting CVE-2022-42703 - Bringing back the stack attack

This write-up analyzes CVE-2022-42703, a complex Linux kernel anon_vma use-after-free that the author turns into a constrained arbitrary-write primitive via down_read_trylock, then leverages non-randomized exception stacks and hardware breakpoints to corrupt saved registers and produce kernel stack overflows leading to local kernel code execution; it also demonstrates a prefetch-based KASLR/CPU-entry-area disclosure PoC to defeat mitigations.