xguest SELinux Policy documentation

NAME¶

xguest_u - Least privileged xwindows user role. - Security Enhanced Linux Policy

DESCRIPTION¶

xguest_u is an SELinux User defined in the SELinux policy. SELinux users have default roles, xguest_r. The default role has a default type, xguest_t, associated with it.

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

xguest_u:xguest_r:xguest_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 xguest_u user, you would execute:

semanage login -m -s xguest_u __default__

If you want to map the one Linux user (joe) to the SELinux user xguest, you would execute:

$ semanage login -a -s xguest_u joe

USER DESCRIPTION¶

The SELinux user xguest_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 xguest_u is able to X Windows login.

NETWORK¶

The SELinux user xguest_u is able to listen on the following tcp ports.

1716

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

53,853

8955

4713

4331,5001

80,81,443,488,8008,8009,8443,9000

8080,8118,8123,10001-10010

3128,3401,4827

843,1935

21,989,990

631,8610-8614

32768-60999

all ports without defined types

8000,9433,16001

8036

8081

9080

88,750,4444

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

53,853

8955

4713

4331,5001

80,81,443,488,8008,8009,8443,9000

8080,8118,8123,10001-10010

3128,3401,4827

843,1935

21,989,990

631,8610-8614

32768-60999

all ports without defined types

8000,9433,16001

8036

8081

9080

88,750,4444

BOOLEANS¶

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

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

setsebool -P xguest_connect_network 1

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

setsebool -P xguest_mount_media 1

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

setsebool -P xguest_use_bluetooth 1

If you want to deny all system processes and Linux users to use bluetooth wireless technology, you must turn on the deny_bluetooth boolean. Disabled by default.

setsebool -P deny_bluetooth 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 boolean. Disabled 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. Disabled by default.

setsebool -P deny_ptrace 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 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 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 selinuxuser_execstack boolean. Enabled by default.

setsebool -P selinuxuser_execstack 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 selinuxuser_rw_noexattrfile boolean. Enabled by default.

setsebool -P selinuxuser_rw_noexattrfile 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 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

HOME_EXEC¶

The SELinux user xguest_u is able execute home content files.

TRANSITIONS¶

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

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

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

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

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

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

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

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

MANAGED FILES¶

The SELinux process type xguest_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.

alsa_home_t

/home/[^/]+/.asoundrc

auth_cache_t

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

chrome_sandbox_tmpfs_t

gconf_tmp_t

/tmp/gconfd-[^/]+/.*

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(/.+)?

noxattrfs

all files on file systems which do not support extended attributes

pulseaudio_tmpfs_t

pulseaudio_tmpfsfile

session_dbusd_tmp_t

/var/run/user/[0-9]+/bus
/var/run/user/[0-9]+/dbus(/.*)?
/var/run/user/[0-9]+/dbus-1(/.*)?

usbfs_t

user_fonts_cache_t

/root/.fontconfig(/.*)?
/root/.fonts/auto(/.*)?
/root/.fonts.cache-.*
/root/.cache/fontconfig(/.*)?
/home/[^/]+/.fontconfig(/.*)?
/home/[^/]+/.fonts/auto(/.*)?
/home/[^/]+/.fonts.cache-.*
/home/[^/]+/.cache/fontconfig(/.*)?

user_home_type

all user home files

user_tmp_t

/tmp/libdnf..+
/dev/shm/mono.*
/var/run/user/[^/]+
/tmp/.ICE-unix(/.*)?
/tmp/.X11-unix(/.*)?
/dev/shm/pulse-shm.*
/tmp/.X0-lock
/var/run/user
/tmp/hsperfdata_root
/var/tmp/hsperfdata_root
/home/[^/]+/tmp
/home/[^/]+/.tmp
/var/run/user/[0-9]+
/tmp/gconfd-[^/]+

user_tmp_type

all user tmp files

xserver_tmpfs_t

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 .

Source file:	xguest_selinux.8.en.gz (from selinux-policy-doc 38.1.35-2.el9_4)
Source last updated:	2024-05-12 12:19:56
Converted to HTML:	2024-06-22 22:26:28