The PAM module tries to get the umask value from the following places in the following order:
The GECOS field is split on comma ',' characters. The module also in addition to the umask= entry recognizes pri= entry, which sets the nice priority value for the session, and ulimit= entry, which sets the maximum size of files the processes in the session can create.
Only the session type is provided.
Add the following line to /etc/pam.d/login to set the user specific umask at login:
session optional pam_umask.so umask=0022
pam.conf(5), pam.d(5), pam(7)
pam_umask was written by Thorsten Kukuk <firstname.lastname@example.org>.