xserver_selinux(8)					      SELinux Policy xserver						xserver_selinux(8)

NAME
xserver_selinux - Security Enhanced Linux Policy for the xserver processes DESCRIPTION
Security-Enhanced Linux secures the xserver processes via flexible mandatory access control. The xserver processes execute with the xserver_t SELinux type. You can check if you have these processes running by executing the ps com- mand with the -Z qualifier. For example: ps -eZ | grep xserver_t ENTRYPOINTS
The xserver_t SELinux type can be entered via the unlabeled_t, proc_type, file_type, mtrr_device_t, filesystem_type, sysctl_type, xserver_exec_t file types. The default entrypoint paths for the xserver_t domain are the following: all files on the system, /dev/cpu/mtrr, /usr/bin/Xair, /usr/bin/Xorg, /usr/bin/Xvnc, /usr/bin/Xephyr, /usr/bin/x11vnc, /usr/X11R6/bin/X, /usr/X11R6/bin/Xorg, /usr/X11R6/bin/Xipaq, /usr/X11R6/bin/XFree86, /usr/X11R6/bin/Xwrapper PROCESS TYPES
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 ps Policy governs the access confined processes have to files. SELinux xserver policy is very flexible allowing users to setup their xserver processes in as secure a method as possible. The following process types are defined for xserver: xserver_t Note: semanage permissive -a xserver_t can be used to make the process type xserver_t permissive. SELinux does not deny access to permis- sive process types, but the AVC (SELinux denials) messages are still generated. BOOLEANS
SELinux policy is customizable based on least access required. xserver policy is extremely flexible and has several booleans that allow you to manipulate the policy and run xserver with the tightest access possible. If you want to allows XServer to execute writable memory, you must turn on the xserver_execmem boolean. Disabled by default. setsebool -P xserver_execmem 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 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 allow all daemons the ability to read/write terminals, you must turn on the daemons_use_tty boolean. Disabled by default. setsebool -P daemons_use_tty 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 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 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 control the ability to mmap a low area of the address space, as configured by /proc/sys/kernel/mmap_min_addr, you must turn on the mmap_low_allowed boolean. Disabled by default. setsebool -P mmap_low_allowed 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. Enabled by default. setsebool -P nscd_use_shm 1 If you want to disable kernel module loading, you must turn on the secure_mode_insmod boolean. Enabled by default. setsebool -P secure_mode_insmod 1 If you want to boolean to determine whether the system permits loading policy, setting enforcing mode, and changing boolean values. Set this to true and you have to reboot to set it back, you must turn on the secure_mode_policyload boolean. Enabled by default. setsebool -P secure_mode_policyload 1 If you want to allow unconfined executables to make their heap memory executable. Doing this is a really bad idea. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla, you must turn on the selin- uxuser_execheap boolean. Disabled by default. setsebool -P selinuxuser_execheap 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 selin- uxuser_execstack boolean. Enabled by default. setsebool -P selinuxuser_execstack 1 If you want to support ecryptfs home directories, you must turn on the use_ecryptfs_home_dirs boolean. Disabled by default. setsebool -P use_ecryptfs_home_dirs 1 If you want to support fusefs home directories, you must turn on the use_fusefs_home_dirs boolean. Disabled by default. setsebool -P use_fusefs_home_dirs 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 confined virtual guests to interact with the xserver, you must turn on the virt_use_xserver boolean. Disabled by default. setsebool -P virt_use_xserver 1 If you want to allow ZoneMinder to run su/sudo, you must turn on the zoneminder_run_sudo boolean. Disabled by default. setsebool -P zoneminder_run_sudo 1 NSSWITCH DOMAIN
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server for the xserver_t, you must turn on the authlogin_nsswitch_use_ldap boolean. setsebool -P authlogin_nsswitch_use_ldap 1 If you want to allow confined applications to run with kerberos for the xserver_t, you must turn on the kerberos_enabled boolean. setsebool -P kerberos_enabled 1 PORT TYPES
SELinux defines port types to represent TCP and UDP ports. You can see the types associated with a port by using the following command: semanage port -l Policy governs the access confined processes have to these ports. SELinux xserver policy is very flexible allowing users to setup their xserver processes in as secure a method as possible. The following port types are defined for xserver: xserver_port_t Default Defined Ports: tcp 6000-6020 MANAGED FILES
The SELinux process type xserver_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. file_type all files on the system FILE CONTEXTS
SELinux requires files to have an extended attribute to define the file type. You can see the context of a file using the -Z option to ls Policy governs the access confined processes have to these files. SELinux xserver policy is very flexible allowing users to setup their xserver processes in as secure a method as possible. STANDARD FILE CONTEXT SELinux defines the file context types for the xserver, if you wanted to store files with these types in a diffent paths, you need to exe- cute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk. semanage fcontext -a -t xserver_etc_t '/srv/xserver/content(/.*)?' restorecon -R -v /srv/myxserver_content Note: SELinux often uses regular expressions to specify labels that match multiple files. The following file types are defined for xserver: xserver_etc_t - Set files with the xserver_etc_t type, if you want to store xserver files in the /etc directories. xserver_exec_t - Set files with the xserver_exec_t type, if you want to transition an executable to the xserver_t domain. Paths: /usr/bin/Xair, /usr/bin/Xorg, /usr/bin/Xvnc, /usr/bin/Xephyr, /usr/bin/x11vnc, /usr/X11R6/bin/X, /usr/X11R6/bin/Xorg, /usr/X11R6/bin/Xipaq, /usr/X11R6/bin/XFree86, /usr/X11R6/bin/Xwrapper xserver_log_t - Set files with the xserver_log_t type, if you want to treat the data as xserver log data, usually stored under the /var/log directory. Paths: /var/[xgkw]dm(/.*)?, /usr/var/[xgkw]dm(/.*)?, /var/log/gdm(3)?(/.*)?, /var/log/Xorg.*, /var/log/XFree86.*, /var/log/lightdm(/.*)?, /var/log/nvidia-installer.log.* xserver_tmpfs_t - Set files with the xserver_tmpfs_t type, if you want to store xserver files on a tmpfs file system. xserver_var_lib_t - Set files with the xserver_var_lib_t type, if you want to store the xserver files under the /var/lib directory. xserver_var_run_t - Set files with the xserver_var_run_t type, if you want to store the xserver files under the /run or /var/run directory. Paths: /var/run/xorg(/.*)?, /var/run/video.rom Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels. 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 port can also be used to manipulate the port definitions 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), xserver(8), semanage(8), restorecon(8), chcon(1), sepolicy(8) , setsebool(8) xserver 14-06-10 xserver_selinux(8)