---
name: "pam_umask"
section: "8"
platform: "linux"
package: "pam"
version: "1.7.3-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pam_umask"
---

# pam\_umask(8)

PAM module to set the file mode creation mask

## 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.conf/5.md), [**pam.d**(5)](/pam.d/5.md), [**pam**(8)](/pam/8.md)

## AUTHOR

pam\_umask was written by Thorsten Kukuk \<kukuk@thkukuk.de\>.