I found a Linux kernel security bug (in AF_UNIX) and decided to write a kernel exploit for it that can go straight from "attacker can run arbitrary native code in a seccomp-sandboxed Chrome renderer" to kernel compromise:
https://googleprojectzero.blogspot.com/2025/08/from-chrome-renderer-code-exec-to-kernel.html
This post includes fun things like:
- a nice semi-arbitrary read primitive combined with an annoying write primitive
- slowing down usercopy without FUSE or userfaultfd
- CONFIG_RANDOMIZE_KSTACK_OFFSET as an exploitation aid
- a rarely-used kernel feature that Chrome doesn't need but is reachable in the Chrome sandbox
- sched_getcpu() usable inside Chrome renderers despite getcpu being blocked by seccomp (thanks to vDSO)