user_screen_selinux - Man Page

Security-Enhanced Linux secures the user_screen processes via flexible mandatory access control.

The user_screen processes execute with the user_screen_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.

For example:

ps -eZ | grep user_screen_t

The user_screen_t SELinux type can be entered via the screen_exec_t file type.

The default entrypoint paths for the user_screen_t domain are the following:

/usr/bin/tmux, /usr/bin/screen

SELinux defines process types (domains) for each process running on the system

You can see the context of a process using the -Z option to psbP

Policy governs the access confined processes have to files. SELinux user_screen policy is very flexible allowing users to setup their user_screen processes in as secure a method as possible.

The following process types are defined for user_screen:

user_screen_t

Note: semanage permissive -a user_screen_t can be used to make the process type user_screen_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.

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

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 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 determine whether screen can use fsetid/setuid/setgid capability, you must turn on the screen_allow_session_sharing boolean. Disabled by default.

setsebool -P screen_allow_session_sharing 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

The SELinux process type user_screen_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.

faillog_t

/var/log/btmp.*
/run/faillock(/.*)?
/var/log/faillog.*
/var/log/tallylog.*

initrc_var_run_t

/run/utmp
/run/random-seed
/run/runlevel.dir
/run/setmixer_flag

krb5_host_rcache_t

/var/tmp/krb5_0.rcache2
/var/cache/krb5rcache(/.*)?
/var/tmp/nfs_0
/var/tmp/DNS_25
/var/tmp/host_0
/var/tmp/imap_0
/var/tmp/HTTP_23
/var/tmp/HTTP_48
/var/tmp/ldap_55
/var/tmp/ldap_487
/var/tmp/ldapmap1_0

user_tmp_type

all user tmp files

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.

This manual page was auto-generated using sepolicy manpage .

selinux(8), user_screen(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8)

user_selinux(8).