user_selinux (8) - Linux Manuals

user_selinux: Generic unprivileged user - Security Enhanced Linux Policy

NAME

user_u - Generic unprivileged user - Security Enhanced Linux Policy

DESCRIPTION

user_u is an SELinux User defined in the SELinux policy. SELinux users have default roles, user_r. The default role has a default type, user_t, associated with it.

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

user_u:user_r:user_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 user_u user, you would execute:

semanage login -m -s user_u __default__

USER DESCRIPTION

The SELinux user user_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 user_u is able to X Windows login.

NETWORK

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

6000-6020

all ports with out defined types

all ports > 1024

3689

32768-61000

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

53

8955

all ports

9080

88,750,4444

all ports with out defined types

5432,9898

389,636,3268,7389

111

32768-61000

all ports < 1024

The SELinux user user_u is able to listen on the following udp ports.

32768-61000

all ports with out defined types

all ports > 1024

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

53

8955

all ports

9080

88,750,4444

all ports with out defined types

5432,9898

389,636,3268,7389

111

32768-61000

all ports < 1024

BOOLEANS

SELinux policy is customizable based on least access required. user policy is extremely flexible and has several booleans that allow you to manipulate the policy and run user 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 authlogin_nsswitch_use_ldap boolean. Disabled by default.

setsebool -P authlogin_nsswitch_use_ldap 1

If you want to determine whether crond can execute jobs in the user domain as opposed to the the generic cronjob domain, you must turn on the cron_userdomain_transition boolean. Enabled by default.

setsebool -P cron_userdomain_transition 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. 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 determine whether calling user domains can execute Git daemon in the git_session_t domain, you must turn on the git_session_users boolean. Enabled by default.

setsebool -P git_session_users 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. Disabled 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 determine whether calling user domains can execute Polipo daemon in the polipo_session_t domain, you must turn on the polipo_session_users boolean. Disabled by default.

setsebool -P polipo_session_users 1

If you want to allow pppd to be run for a regular user, you must turn on the pppd_for_user boolean. Disabled by default.

setsebool -P pppd_for_user 1

If you want to disallow programs, such as newrole, from transitioning to administrative user domains, you must turn on the secure_mode boolean. Enabled by default.

setsebool -P secure_mode 1

If you want to allow regular users direct dri device access, you must turn on the selinuxuser_direct_dri_enabled boolean. Enabled by default.

setsebool -P selinuxuser_direct_dri_enabled 1

If you want to allow all unconfined executables to use libraries requiring text relocation that are not labeled textrel_shlib_t, you must turn on the selinuxuser_execmod boolean. Enabled by default.

setsebool -P selinuxuser_execmod 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 users to connect to the local mysql server, you must turn on the selinuxuser_mysql_connect_enabled boolean. Disabled by default.

setsebool -P selinuxuser_mysql_connect_enabled 1

If you want to allow confined users the ability to execute the ping and traceroute commands, you must turn on the selinuxuser_ping boolean. Enabled by default.

setsebool -P selinuxuser_ping 1

If you want to allow users to connect to PostgreSQL, you must turn on the selinuxuser_postgresql_connect_enabled boolean. Disabled by default.

setsebool -P selinuxuser_postgresql_connect_enabled 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. Disabled by default.

setsebool -P selinuxuser_rw_noexattrfile 1

If you want to allow user music sharing, you must turn on the selinuxuser_share_music boolean. Disabled by default.

setsebool -P selinuxuser_share_music 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 selinuxuser_tcp_server boolean. Disabled by default.

setsebool -P selinuxuser_tcp_server 1

If you want to allow users to run UDP servers (bind to ports and accept connection from the same domain and outside users) disabling this may break avahi discovering services on the network and other udp related services, you must turn on the selinuxuser_udp_server boolean. Disabled by default.

setsebool -P selinuxuser_udp_server 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 allow unprivileged user to create and transition to svirt domains, you must turn on the unprivuser_use_svirt boolean. Disabled by default.

setsebool -P unprivuser_use_svirt 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. Disabled by default.

setsebool -P xdm_sysadm_login 1

If you want to allows clients to write to the X server shared memory segments, you must turn on the xserver_clients_write_xshm boolean. Disabled by default.

setsebool -P xserver_clients_write_xshm 1

If you want to support X userspace object manager, you must turn on the xserver_object_manager boolean. Enabled by default.

setsebool -P xserver_object_manager 1

HOME_EXEC

The SELinux user user_u is able execute home content files.

TRANSITIONS

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

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

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

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

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

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

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

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

MANAGED FILES

The SELinux process type user_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(/.*)?

bluetooth_helper_tmp_t

bluetooth_helper_tmpfs_t

cgroup_t

        /sys/fs/cgroup

chrome_sandbox_tmpfs_t

cifs_t

games_data_t

        /var/games(/.*)?

       /var/lib/games(/.*)?

gconf_tmp_t

        /tmp/gconfd-[^/]+/.*

git_user_content_t

        /home/[^/]+/public_git(/.*)?

gnome_home_type

gpg_agent_tmp_t

        /home/[^/]+/.gnupg/log-socket

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(/.+)?

irc_home_t

        /home/[^/]+/.irssi(/.*)?

       /home/[^/]+/irclog(/.*)?

       /home/[^/]+/.ircmotd

mail_spool_t

        /var/mail(/.*)?

       /var/spool/imap(/.*)?

       /var/spool/mail(/.*)?

       /var/spool/smtpd(/.*)?

mqueue_spool_t

        /var/spool/(client)?mqueue(/.*)?

       /var/spool/mqueue.in(/.*)?

noxattrfs

        all files on file systems which do not support extended attributes

pulseaudio_tmpfs_t

pulseaudio_tmpfsfile

sandbox_file_t

sandbox_tmpfs_type

        all sandbox content in tmpfs file systems

screen_home_t

        /root/.screen(/.*)?

       /home/[^/]+/.screen(/.*)?

       /home/[^/]+/.screenrc

       /home/[^/]+/.tmux.conf

security_t

        /selinux

usbfs_t

user_fonts_cache_t

        /root/.fontconfig(/.*)?

       /root/.fonts/auto(/.*)?

       /root/.fonts.cache-.*

       /home/[^/]+/.fontconfig(/.*)?

       /home/[^/]+/.fonts/auto(/.*)?

       /home/[^/]+/.fonts.cache-.*

user_home_type

        all user home files

user_tmp_t

        /dev/shm/mono.*

       /var/run/user(/.*)?

       /tmp/.X11-unix(/.*)?

       /tmp/.ICE-unix(/.*)?

       /dev/shm/pulse-shm.*

       /tmp/.X0-lock

       /tmp/hsperfdata_root

       /var/tmp/hsperfdata_root

       /home/[^/]+/tmp

       /home/[^/]+/.tmp

       /tmp/gconfd-[^/]+

user_tmp_type

        all user tmp files

virt_image_type

        all virtual image 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.