guest_selinux(8) guest SELinux Policy documentation guest_selinux(8)NAME
guest_u - Least privledge terminal user role. - 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
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__
If you want to map the one Linux user (joe) to the SELinux user guest,
you would execute:
$ semanage login -a -s guest_u joe
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.
SUDOX WINDOWS LOGIN
The SELinux user guest_u is not able to X Windows login.
NETWORK
The SELinux user guest_u is able to listen on the following tcp ports.
32768-61000
all ports with out defined types
The SELinux user guest_u is able to connect to the following tcp ports.
53
32768-61000
88,750,4444
9080
111
all ports with out defined types
all ports < 1024
389,636,3268,7389
The SELinux user guest_u is able to listen on the following udp ports.
32768-61000
all ports with out defined types
The SELinux user guest_u is able to connect to the following tcp ports.
53
32768-61000
88,750,4444
9080
111
all ports with out defined types
all ports < 1024
389,636,3268,7389
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 users to resolve user passwd entries directly from
ldap rather then using a sssd server, you must turn on the authlo‐
gin_nsswitch_use_ldap boolean. Disabled by default.
setsebool -P authlogin_nsswitch_use_ldap 1
If you want to deny user domains applications to map a memory region as
both executable and writable, this is dangerous and the executable
should be reported in bugzilla, you must turn on the deny_execmem bool‐
ean. Enabled by default.
setsebool -P deny_execmem 1
If you want to deny any process from ptracing or debugging any other
processes, you must turn on the deny_ptrace boolean. Enabled by
default.
setsebool -P deny_ptrace 1
If you want to allow all domains to use other domains file descriptors,
you must turn on the domain_fd_use boolean. Enabled by default.
setsebool -P domain_fd_use 1
If you want to allow all domains to have the kernel load modules, you
must turn on the domain_kernel_load_modules boolean. Disabled by
default.
setsebool -P domain_kernel_load_modules 1
If you want to allow all domains to execute in fips_mode, you must turn
on the fips_mode boolean. Enabled by default.
setsebool -P fips_mode 1
If you want to enable reading of urandom for all domains, you must turn
on the global_ssp boolean. Disabled by default.
setsebool -P global_ssp 1
If you want to allow httpd cgi support, you must turn on the
httpd_enable_cgi boolean. Enabled by default.
setsebool -P httpd_enable_cgi 1
If you want to unify HTTPD handling of all content files, you must turn
on the httpd_unified boolean. Disabled by default.
setsebool -P httpd_unified 1
If you want to allow confined applications to run with kerberos, you
must turn on the kerberos_enabled boolean. Enabled by default.
setsebool -P kerberos_enabled 1
If you want to allow logging in and using the system from /dev/console,
you must turn on the login_console_enabled boolean. Enabled by default.
setsebool -P login_console_enabled 1
If you want to allow system to run with NIS, you must turn on the
nis_enabled boolean. Disabled by default.
setsebool -P nis_enabled 1
If you want to allow confined applications to use nscd shared memory,
you must turn on the nscd_use_shm boolean. Disabled by default.
setsebool -P nscd_use_shm 1
If you want to disallow programs, such as newrole, from transitioning
to administrative user domains, you must turn on the secure_mode bool‐
ean. Disabled by default.
setsebool -P secure_mode 1
If you want to allow unconfined executables to make their stack exe‐
cutable. This should never, ever be necessary. Probably indicates a
badly coded executable, but could indicate an attack. This executable
should be reported in bugzilla, you must turn on the selinuxuser_exec‐
stack boolean. Enabled by default.
setsebool -P selinuxuser_execstack 1
If you want to allow user to use ssh chroot environment, you must turn
on the selinuxuser_use_ssh_chroot boolean. Disabled by default.
setsebool -P selinuxuser_use_ssh_chroot 1
If you want to allow ssh logins as sysadm_r:sysadm_t, you must turn on
the ssh_sysadm_login boolean. Disabled by default.
setsebool -P ssh_sysadm_login 1
If you want to support NFS home directories, you must turn on the
use_nfs_home_dirs boolean. Disabled by default.
setsebool -P use_nfs_home_dirs 1
If you want to support SAMBA home directories, you must turn on the
use_samba_home_dirs boolean. Disabled by default.
setsebool -P use_samba_home_dirs 1
If you want to allow the graphical login program to login directly as
sysadm_r:sysadm_t, you must turn on the xdm_sysadm_login boolean.
Enabled by default.
setsebool -P xdm_sysadm_login 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 cur‐
rent 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 fol‐
lowing 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(/.*)?
cifs_t
httpd_user_content_t
/home/[^/]*/((www)|(web)|(public_html))(/.+)?
httpd_user_htaccess_t
/home/[^/]*/((www)|(web)|(public_html))(/.*)?/.htaccess
httpd_user_ra_content_t
/home/[^/]*/((www)|(web)|(public_html))(/.*)?/logs(/.*)?
httpd_user_rw_content_t
httpd_user_script_exec_t
/home/[^/]*/((www)|(web)|(public_html))/cgi-bin(/.+)?
nfs_t
user_home_type
all user home files
user_tmp_type
all user tmp files
user_tmpfs_type
all user content in tmpfs file systems
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 pol‐
icy modules.
semanage boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux pol‐
icy settings.
AUTHOR
This manual page was auto-generated using sepolicy manpage .
SEE ALSOselinux(8), guest(8), semanage(8), restorecon(8), chcon(1), sepolicy(8)
, setsebool(8)mgrepl@redhat.com guest guest_selinux(8)
