guest_selinux(8) - Linux man page

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_t: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

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.

ldap_port_t: 389,636,3268

dns_port_t: 53

kerberos_port_t: 88,750

ocsp_port_t: 9080

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

ldap_port_t: 389,636,3268

dns_port_t: 53

kerberos_port_t: 88,750

ocsp_port_t: 9080

Booleans

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

If you want to allow xguest users to mount removable media, you must turn on the xguest_mount_media boolean.

setsebool -P xguest_mount_media 1

If you want to allow xguest to configure Network Manager and connect to apache ports, you must turn on the xguest_connect_network boolean.

setsebool -P xguest_connect_network 1

If you want to allow xguest to use blue tooth devices, you must turn on the xguest_use_bluetooth boolean.

setsebool -P xguest_use_bluetooth 1

If you want to allow xguest users to mount removable media, you must turn on the xguest_mount_media boolean.

setsebool -P xguest_mount_media 1

If you want to allow xguest to configure Network Manager and connect to apache ports, you must turn on the xguest_connect_network boolean.

setsebool -P xguest_connect_network 1

If you want to allow xguest to use blue tooth devices, you must turn on the xguest_use_bluetooth boolean.

setsebool -P xguest_use_bluetooth 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:
search -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:
$ search -A -s guest_t -c process -p transition

Managed Files

The SELinux process type guest_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.

anon_inodefs_t

auth_cache_t

/var/cache/coolkey(/.*)?

httpd_user_content_t

/home/[^/]*/((www)|(web)|(public_html))(/.+)?

httpd_user_htaccess_t
httpd_user_ra_content_t
httpd_user_rw_content_t
httpd_user_script_exec_t
initrc_tmp_t
mnt_t

/mnt(/[^/]*)

/mnt(/[^/]*)?

/rhev(/[^/]*)?

/media(/[^/]*)

/media(/[^/]*)?

/etc/rhgb(/.*)?

/media/.hal-.*

/net

/afs

/misc

/rhev

nfs_t
tmp_t

/tmp

/usr/tmp

/var/tmp

/var/tmp/vi.recover

user_home_type

all user home files

user_tmp_t

/tmp/gconfd-.*

user_tmpfs_t

/dev/shm/mono.*

/dev/shm/pulse-shm.*

Commands

semanage fcontext can also be used to manipulate default file context mappings.

semanage permissive can also be used to manipulate whether or not a process type is permissive.

semanage module can also be used to enable/disable/install/remove policy modules.

semanage boolean can also be used to manipulate the booleans

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

Author

This manual page was auto-generated using sepolicy manpage by mgrepl.