guest_selinux

Section: guest SELinux Policy documentation (8)
Updated: guest
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NAME

guest_u - Least privledge terminal user - Security Enhanced Linux Policy

DESCRIPTION

guest_u is an SELinux User defined in the SELinux policy. SELinux users have default roles, guest_r. The default role has a default type, guest_t, associated with it.

The SELinux user will usually login to a system with a context that looks like:

guest_u:guest_r:guest_u:s0-s0:c0.c1023

Linux users are automatically assigned an SELinux users at login. Login programs use the SELinux User to assign initial context to the user's shell.

SELinux policy uses the context to control the user's access.

By default all users are assigned to the SELinux user via the __default__ flag

On Targeted policy systems the __default__ user is assigned to the unconfined_u SELinux user.

You can list all Linux User to SELinux user mapping using:

semanage login -l

If you wanted to change the default user mapping to use the guest_u user, you would execute:

semanage login -m -s guest_u __default__

USER DESCRIPTION

The SELinux user guest_u is defined in policy as a unprivileged user. SELinux prevents unprivileged users from doing administration tasks without transitioning to a different role.

SUDO

The SELinux type guest_t is not allowed to execute sudo.

X WINDOWS LOGIN

The SELinux user guest_u is not able to X Windows login.

NETWORK

The SELinux user guest_u is able to connect to the following tcp ports.

dns_port_t: 53

ldap_port_t: 389,636,3268

kerberos_port_t: 88,750

ocsp_port_t: 9080

BOOLEANS

SELinux policy is customizable based on least access required. guest_t policy is extremely flexible and has several booleans that allow you to manipulate the policy and run guest_t with the tightest access possible.

If you want to allow users to connect to mysql, you must turn on the allow_user_mysql_connect boolean.

setsebool -P allow_user_mysql_connect 1

If you want to allow user processes to change their priority, you must turn on the user_setrlimit boolean.

setsebool -P user_setrlimit 1

If you want to control users use of ping and traceroute, you must turn on the user_ping boolean.

setsebool -P user_ping 1

If you want to allow w to display everyone, you must turn on the user_ttyfile_stat boolean.

setsebool -P user_ttyfile_stat 1

If you want to allow regular users direct dri device access, you must turn on the user_direct_dri boolean.

setsebool -P user_direct_dri 1

If you want to allow user to r/w files on filesystems that do not have extended attributes (FAT, CDROM, FLOPPY), you must turn on the user_rw_noexattrfile boolean.

setsebool -P user_rw_noexattrfile 1

If you want to allow users to run TCP servers (bind to ports and accept connection from the same domain and outside users) disabling this forces FTP passive mode and may change other protocols, you must turn on the user_tcp_server boolean.

setsebool -P user_tcp_server 1

If you want to allow regular users direct mouse access, you must turn on the user_direct_mouse boolean.

setsebool -P user_direct_mouse 1

If you want to allow users to connect to PostgreSQL, you must turn on the allow_user_postgresql_connect boolean.

setsebool -P allow_user_postgresql_connect 1

HOME_EXEC

The SELinux user guest_u is able execute home content files.

TRANSITIONS

Three things can happen when guest_t attempts to execute a program.

1. SELinux Policy can deny guest_t from executing the program.

2. SELinux Policy can allow guest_t to execute the program in the current user type.

Execute the following to see the types that the SELinux user guest_t can execute without transitioning:

sesearch -A -s guest_t -c file -p execute_no_trans

3. SELinux can allow guest_t to execute the program and transition to a new type.

Execute the following to see the types that the SELinux user guest_t can execute and transition:

$ sesearch -A -s guest_t -c process -p transition

COMMANDS

semanage login can also be used to manipulate the Linux User to SELinux User mappings

semanage user can also be used to manipulate SELinux user definitions.

system-config-selinux is a GUI tool available to customize SELinux policy settings.

AUTHOR

This manual page was autogenerated by genuserman.py.

This document was created by man2html, using the manual pages.
Time: 05:34:26 GMT, December 24, 2015