What must be configured to ensure that Samba passwords remain in sync with user Linux passwords?

To ensure that Samba passwords remain in sync with user Linux passwords, configuring the PAM (Pluggable Authentication Modules) system to include pam_smbpass.so is crucial. This module interfaces with the Samba password database, facilitating synchronization between Samba and Linux user accounts. When properly configured, it allows changes made to user passwords via the standard Unix tools (like passwd) to also reflect in Samba's password database.

This synchronization is essential for environments where both Linux and Samba services are utilized, ensuring users have a seamless experience regardless of whether they are accessing resources via SMB/CIFS or local Unix sessions. By integrating with PAM in this way, any updates to the password via standard Unix mechanisms are propagated to Samba, thus maintaining consistent credentials across both services.

Other options do not effectively achieve this synchronization or are not feasible solutions. Thus, the implementation of pam_smbpass.so is recognized as the correct way to synchronize passwords effectively.