The keyring separates staging from execution, payload can be written by a different process at a different time with no file, no memfd, no open fd in /proc/pid/

The keyring separates staging from execution, payload can be written by a different process at a different time with no file, no memfd, no open fd in /proc/pid/fd, by the time the loader runs, the payload only exists in kernel memory, direct userland exec still needs to read from somewhere visible