PAM_UMASK(8)		       Linux-PAM Manual			  PAM_UMASK(8)

NAME
       pam_umask - PAM module to set the file mode creation mask

SYNOPSIS
       pam_umask.so [debug] [silent] [usergroups] [nousergroups] [umask=mask]

DESCRIPTION
       pam_umask is a PAM module to set the file mode creation mask of the
       current environment. The umask affects the default permissions assigned
       to newly created files.

       The PAM module tries to get the umask value from the following places
       in the following order:

       •   umask= entry in the user's GECOS field (see below for details)

       •   umask= argument

       •   UMASK entry from /etc/login.defs

       •   UMASK= entry from /etc/default/login

       The GECOS field is split on comma ',' characters. Entries must be set
       in its 'other' (sub-)field (the 5th field within the GECOS field),
       which could be done, for example, using chfn --other. In addition to
       the umask= entry, the module also recognizes the pri= entry, which sets
       the nice priority value for the session, and the ulimit= entry, which
       sets the maximum size of files the processes in the session can create.

OPTIONS
       debug
	   Print debug information.

       silent
	   Don't print informative messages.

       usergroups
	   If the user is not root and the username is the same as primary
	   group name, the umask group bits are set to be the same as owner
	   bits (examples: 022 -> 002, 077 -> 007).

       nousergroups
	   This is the direct opposite of the usergroups option described
	   above, which can be useful in case pam_umask has been compiled with
	   usergroups enabled by default and you want to disable it at
	   runtime.

       umask=mask
	   Sets the calling process's file mode creation mask (umask) to mask
	   & 0777. The value is interpreted as Octal.

MODULE TYPES PROVIDED
       Only the session type is provided.

RETURN VALUES
       PAM_SUCCESS
	   The new umask was set successfully.

       PAM_BUF_ERR
	   Memory buffer error.

       PAM_CONV_ERR
	   The conversation method supplied by the application failed to
	   obtain the username.

       PAM_INCOMPLETE
	   The conversation method supplied by the application returned
	   PAM_CONV_AGAIN.

       PAM_SERVICE_ERR
	   No username was given.

       PAM_USER_UNKNOWN
	   User not known.

EXAMPLES
       Add the following line to /etc/pam.d/login to set the user specific
       umask at login:

		   session optional pam_umask.so umask=0022



SEE ALSO
       pam.conf(5), pam.d(5), pam(8)

AUTHOR
       pam_umask was written by Thorsten Kukuk <kukuk@thkukuk.de>.

Linux-PAM			  06/19/2025			  PAM_UMASK(8)