On Mon, Jul 06, 2020 at 01:17:16PM -0700, Kees Cook wrote: > For both pidfd and seccomp, the __user pointer is not used. Update > __receive_fd() to make writing to ufd optional via a NULL check. However, > for the receive_fd_user() wrapper, ufd is NULL checked so an -EFAULT > can be returned to avoid changing the SCM_RIGHTS interface behavior. Add > new wrapper receive_fd() for pidfd and seccomp that does not use the ufd > argument. For the new helper, the allocated fd needs to be returned on > success. Update the existing callers to handle it. Oh here we go, I'll take the last comment back.