1xserver_selinux(8) SELinux Policy xserver xserver_selinux(8)
2
6 xserver_selinux - Security Enhanced Linux Policy for the xserver pro‐
7 cesses
8
10 Security-Enhanced Linux secures the xserver processes via flexible
11 mandatory access control.
12 The xserver processes execute with the xserver_t SELinux type. You can
14 check if you have these processes running by executing the ps command
15 with the -Z qualifier.
16 For example:
18 ps -eZ | grep xserver_t
20
24 The xserver_t SELinux type can be entered via the xserver_exec_t file
25 type.
26 The default entrypoint paths for the xserver_t domain are the follow‐
28 ing:
29 /usr/bin/nvidia.*, /usr/bin/Xair, /usr/bin/Xorg, /usr/bin/Xvnc,
31 /usr/bin/Xephyr, /usr/bin/x11vnc, /usr/X11R6/bin/X, /usr/bin/Xwayland,
32 /usr/X11R6/bin/Xorg, /usr/X11R6/bin/Xipaq, /usr/libexec/Xorg.bin,
33 /usr/X11R6/bin/XFree86, /usr/libexec/Xorg.wrap, /usr/X11R6/bin/Xwrap‐
34 per, /usr/libexec/gsd-backlight-helper
35
37 SELinux defines process types (domains) for each process running on the
38 system
39 You can see the context of a process using the -Z option to ps
41 Policy governs the access confined processes have to files. SELinux
43 xserver policy is very flexible allowing users to setup their xserver
44 processes in as secure a method as possible.
45 The following process types are defined for xserver:
47 xserver_t
49 Note: semanage permissive -a xserver_t can be used to make the process
51 type xserver_t permissive. SELinux does not deny access to permissive
52 process types, but the AVC (SELinux denials) messages are still gener‐
53 ated.
54
57 SELinux policy is customizable based on least access required. xserver
58 policy is extremely flexible and has several booleans that allow you to
59 manipulate the policy and run xserver with the tightest access possi‐
60 ble.
61 If you want to allows XServer to execute writable memory, you must turn
65 on the xserver_execmem boolean. Disabled by default.
66 setsebool -P xserver_execmem 1
68 If you want to support X userspace object manager, you must turn on the
72 xserver_object_manager boolean. Disabled by default.
73 setsebool -P xserver_object_manager 1
75 If you want to deny user domains applications to map a memory region as
79 both executable and writable, this is dangerous and the executable
80 should be reported in bugzilla, you must turn on the deny_execmem bool‐
81 ean. Disabled by default.
82 setsebool -P deny_execmem 1
84 If you want to control the ability to mmap a low area of the address
88 space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on
89 the mmap_low_allowed boolean. Disabled by default.
90 setsebool -P mmap_low_allowed 1
92 If you want to allow system to run with NIS, you must turn on the
96 nis_enabled boolean. Disabled by default.
97 setsebool -P nis_enabled 1
99 If you want to disable kernel module loading, you must turn on the se‐
103 cure_mode_insmod boolean. Disabled by default.
104 setsebool -P secure_mode_insmod 1
106 If you want to allow unconfined executables to make their heap memory
110 executable. Doing this is a really bad idea. Probably indicates a
111 badly coded executable, but could indicate an attack. This executable
112 should be reported in bugzilla, you must turn on the selinuxuser_ex‐
113 echeap boolean. Disabled by default.
114 setsebool -P selinuxuser_execheap 1
116 If you want to allow unconfined executables to make their stack exe‐
120 cutable. This should never, ever be necessary. Probably indicates a
121 badly coded executable, but could indicate an attack. This executable
122 should be reported in bugzilla, you must turn on the selinuxuser_exec‐
123 stack boolean. Enabled by default.
124 setsebool -P selinuxuser_execstack 1
126
130 SELinux defines port types to represent TCP and UDP ports.
131 You can see the types associated with a port by using the following
133 command:
134 semanage port -l
136 Policy governs the access confined processes have to these ports.
139 SELinux xserver policy is very flexible allowing users to setup their
140 xserver processes in as secure a method as possible.
141 The following port types are defined for xserver:
143 xserver_port_t
146 Default Defined Ports:
150 tcp 6000-6020
151
153 The SELinux process type xserver_t can manage files labeled with the
154 following file types. The paths listed are the default paths for these
155 file types. Note the processes UID still need to have DAC permissions.
156 file_type
158 all files on the system
160
163 SELinux requires files to have an extended attribute to define the file
164 type.
165 You can see the context of a file using the -Z option to ls
167 Policy governs the access confined processes have to these files.
169 SELinux xserver policy is very flexible allowing users to setup their
170 xserver processes in as secure a method as possible.
171 STANDARD FILE CONTEXT
173 SELinux defines the file context types for the xserver, if you wanted
175 to store files with these types in a different paths, you need to exe‐
176 cute the semanage command to specify alternate labeling and then use
177 restorecon to put the labels on disk.
178 semanage fcontext -a -t xserver_var_lib_t '/srv/xserver/content(/.*)?'
180 restorecon -R -v /srv/myxserver_content
181 Note: SELinux often uses regular expressions to specify labels that
183 match multiple files.
184 The following file types are defined for xserver:
186 xserver_etc_t
190 - Set files with the xserver_etc_t type, if you want to store xserver
192 files in the /etc directories.
193 xserver_exec_t
197 - Set files with the xserver_exec_t type, if you want to transition an
199 executable to the xserver_t domain.
200 Paths:
203 /usr/bin/nvidia.*, /usr/bin/Xair, /usr/bin/Xorg, /usr/bin/Xvnc,
204 /usr/bin/Xephyr, /usr/bin/x11vnc, /usr/X11R6/bin/X, /usr/bin/Xway‐
205 land, /usr/X11R6/bin/Xorg, /usr/X11R6/bin/Xipaq,
206 /usr/libexec/Xorg.bin, /usr/X11R6/bin/XFree86,
207 /usr/libexec/Xorg.wrap, /usr/X11R6/bin/Xwrapper, /usr/libexec/gsd-
208 backlight-helper
209 xserver_log_t
212 - Set files with the xserver_log_t type, if you want to treat the data
214 as xserver log data, usually stored under the /var/log directory.
215 Paths:
218 /var/[xgkw]dm(/.*)?, /usr/var/[xgkw]dm(/.*)?,
219 /var/log/gdm(3)?(/.*)?, /var/log/Xorg.*, /var/log/XFree86.*,
220 /var/log/lightdm(/.*)?, /var/log/nvidia-installer.log.*
221 xserver_tmpfs_t
224 - Set files with the xserver_tmpfs_t type, if you want to store xserver
226 files on a tmpfs file system.
227 xserver_var_lib_t
231 - Set files with the xserver_var_lib_t type, if you want to store the
233 xserver files under the /var/lib directory.
234 xserver_var_run_t
238 - Set files with the xserver_var_run_t type, if you want to store the
240 xserver files under the /run or /var/run directory.
241 Paths:
244 /var/run/xorg(/.*)?, /var/run/video.rom
245 Note: File context can be temporarily modified with the chcon command.
248 If you want to permanently change the file context you need to use the
249 semanage fcontext command. This will modify the SELinux labeling data‐
250 base. You will need to use restorecon to apply the labels.
251
254 semanage fcontext can also be used to manipulate default file context
255 mappings.
256 semanage permissive can also be used to manipulate whether or not a
258 process type is permissive.
259 semanage module can also be used to enable/disable/install/remove pol‐
261 icy modules.
262 semanage port can also be used to manipulate the port definitions
264 semanage boolean can also be used to manipulate the booleans
266 system-config-selinux is a GUI tool available to customize SELinux pol‐
269 icy settings.
270
273 This manual page was auto-generated using sepolicy manpage .
274
277 selinux(8), xserver(8), semanage(8), restorecon(8), chcon(1), sepol‐
278 icy(8), setsebool(8)
279xserver 23-10-20 xserver_selinux(8)