Sync Samba and Unix password

The pam_smbpass PAM module can be used to sync users’ Samba passwords with their system passwords. 

If a user invokes the passwd command, the password he uses to log in to the system as well as the password he must provide to connect to a Samba share are changed.

To enable this feature, 

add the following line to /etc/pam.d/system-auth below the pam_cracklib.so invocation:

password required /lib/security/pam_smbpass.so nullok use_authtok try_first_pass