The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

24.4 Locking an Account

To lock a user's account, enter:

# passwd -l username

To unlock the account:

# passwd -u username

For more information, see the passwd(1) manual page.