One of the new flags for clone3() in Linux 7.1 is CLONE_AUTOREAP . Using the CLONE_AUTOREAP flag will make child processes auto-reap on exit without the chance of becoming a zombie process.
Another new flag is CLONE_PIDFD_AUTOKILL to tie the child's lifetime to the process ID file descriptor returned from the clone3() system call. The CLONE_PIDFD_AUTOKILL is intended to help with container runtimes, service managers, sandboxed sub-process execution and other workloads where the child processes should die if the parent process crashes.
There is also CLONE_NNP added to allow enforcing no new privileges beavhior (akin to the "no_new_privs" prctl flag on itself) on children at creation time, benefiting spawn-and-sandbox approaches.
These new clone3() flags have been merged via this pull request for Linux 7.1.