NEWUIDMAP(1) NEWUIDMAP(1) (NAME) newuidmap - (UID) (SYNOPSIS) newuidmap pid uid loweruid count [uid loweruid count [ ... ]] (DESCRIPTION) newuidmap UID (user namespace) . newuidmap /proc/[pid]/uid_map UID . Subuid /etc/subuid NSS subid . (mutually exclusive) . (root) /etc/subuid . pid newuidmap : uid UID . loweruid UID . count ( ). newuidmap /proc/[pid]/uid_map pid UID [loweruid, loweruid+count) /etc/subuid . newuidmap . (pid) fd:N N (file descriptor) /proc/[pid] . newuidmap openat(2) uid_map TOCTTOU pid . (OPTIONS) newuidmap . (FILES) /etc/subuid (subordinate user IDs) . /proc/[pid]/uid_map UID . (SEE ALSO) login.defs(5), newusers(8), subuid(5), useradd(8), usermod(8), userdel(8). shadow NEWUIDMAP(1)