On Tue, May 14, 2019 at 11:27:04AM -0400, Arvind Sankar wrote: > It's also much easier to change/customize it for the end > system's requirements rather than setting the process in stone by > putting it inside the kernel. As an example, if you allow unverified external initramfs, it seems to me that it can try to play games that wouldn't be prevented by the in-kernel code: setup /dev in a weird way to try to trick /init, or more easily, replace /init by /bin/sh so you get a shell prompt while only the initramfs is loaded. It's easy to imagine that a system would want to lock itself down to prevent abuses like this. So you might already want an embedded initramfs that can be trusted and that can't be overwritten by an external one even outside the security.ima stuff.
