Re: forkat(int pidfd), execveat(int pidfd), other awful things?

[Jason A. Donenfeld]

> int execve_parent(int parent_pidfd, int root_dirfd, int cgroup_fd, int
> namespace_fd, const char *pathname, char *const argv[], char *const
> envp[]);

A variant on the same scheme would be:

int execve_remote(int pidfd, int root_dirfd, int cgroup_fd, int
namespace_fd, const char *pathname, char *const argv[], char *const
envp[]);

Unpriv'd process calls fork(), and from that fork sends its pidfd
through a unix socket to systemd-sudod, which then calls execve_remote
on that pidfd.

There are a lot of (potentially very bad) ways to skin this cat.