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guest_selinux(8) guest SELinux Policy documentation guest_selinux(8)

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

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

all ports > 500 and < 1024

all ports with out defined types

389,636,3268

53

88,750

111

all ports with out defined types

all ports < 1024

9080

all ports > 500 and < 1024

all ports with out defined types

389,636,3268

53

88,750

111

all ports with out defined types

all ports < 1024

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 direct login to the console device. Required for System 390, you must turn on the allow_console_login boolean. Enabled by default.

setsebool -P allow_console_login 1

If you want to allow all domains to use other domains file descriptors, you must turn on the allow_domain_fd_use boolean. Enabled by default.

setsebool -P allow_domain_fd_use 1

If you want to allow unconfined executables 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 allow_execmem boolean. Enabled by default.

setsebool -P allow_execmem 1

If you want to allow unconfined executables to make their stack executable. 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 allow_execstack boolean. Enabled by default.

setsebool -P allow_execstack 1

If you want to allow confined applications to run with kerberos, you must turn on the allow_kerberos boolean. Enabled by default.

setsebool -P allow_kerberos 1

If you want to allow sysadm to debug or ptrace all processes, you must turn on the allow_ptrace boolean. Disabled by default.

setsebool -P allow_ptrace 1

If you want to allow system to run with NIS, you must turn on the allow_ypbind boolean. Disabled by default.

setsebool -P allow_ypbind 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 use nscd shared memory, you must turn on the nscd_use_shm boolean. Enabled by default.

setsebool -P nscd_use_shm 1

If you want to enabling secure mode disallows programs, such as newrole, from transitioning to administrative user domains, you must turn on the secure_mode boolean. Disabled by default.

setsebool -P secure_mode 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 xdm logins as sysadm, you must turn on the xdm_sysadm_login boolean. Disabled 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 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

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(/.*)?

cifs_t

httpd_user_content_t

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

nfs_t

tmp_t

/tmp
/usr/tmp
/var/tmp
/tmp-inst
/var/tmp-inst
/var/tmp/vi.recover

user_home_type

all user home files

user_tmp_t

/tmp/gconfd-.*
/tmp/gconfd-staff

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 .

SEE ALSO

selinux(8), guest(8), semanage(8), restorecon(8), chcon(1) , setsebool(8), guest_dbusd_selinux(8), guest_dbusd_selinux(8)

guest mgrepl@redhat.com