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. Enabled 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. Enabled 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 disable kernel module loading, you must turn on the se‐
96 cure_mode_insmod boolean. Enabled by default.
97 setsebool -P secure_mode_insmod 1
99 If you want to allow unconfined executables to make their heap memory
103 executable. Doing this is a really bad idea. Probably indicates a
104 badly coded executable, but could indicate an attack. This executable
105 should be reported in bugzilla, you must turn on the selinuxuser_ex‐
106 echeap boolean. Disabled by default.
107 setsebool -P selinuxuser_execheap 1
109 If you want to allow unconfined executables to make their stack exe‐
113 cutable. This should never, ever be necessary. Probably indicates a
114 badly coded executable, but could indicate an attack. This executable
115 should be reported in bugzilla, you must turn on the selinuxuser_exec‐
116 stack boolean. Enabled by default.
117 setsebool -P selinuxuser_execstack 1
119
123 SELinux defines port types to represent TCP and UDP ports.
124 You can see the types associated with a port by using the following
126 command:
127 semanage port -l
129 Policy governs the access confined processes have to these ports.
132 SELinux xserver policy is very flexible allowing users to setup their
133 xserver processes in as secure a method as possible.
134 The following port types are defined for xserver:
136 xserver_port_t
139 Default Defined Ports:
143 tcp 6000-6020
144
146 The SELinux process type xserver_t can manage files labeled with the
147 following file types. The paths listed are the default paths for these
148 file types. Note the processes UID still need to have DAC permissions.
149 file_type
151 all files on the system
153
156 SELinux requires files to have an extended attribute to define the file
157 type.
158 You can see the context of a file using the -Z option to ls
160 Policy governs the access confined processes have to these files.
162 SELinux xserver policy is very flexible allowing users to setup their
163 xserver processes in as secure a method as possible.
164 STANDARD FILE CONTEXT
166 SELinux defines the file context types for the xserver, if you wanted
168 to store files with these types in a diffent paths, you need to execute
169 the semanage command to specify alternate labeling and then use re‐
170 storecon to put the labels on disk.
171 semanage fcontext -a -t xserver_log_t '/srv/myxserver_content(/.*)?'
173 restorecon -R -v /srv/myxserver_content
174 Note: SELinux often uses regular expressions to specify labels that
176 match multiple files.
177 The following file types are defined for xserver:
179 xserver_etc_t
183 - Set files with the xserver_etc_t type, if you want to store xserver
185 files in the /etc directories.
186 xserver_exec_t
190 - Set files with the xserver_exec_t type, if you want to transition an
192 executable to the xserver_t domain.
193 Paths:
196 /usr/bin/nvidia.*, /usr/bin/Xair, /usr/bin/Xorg, /usr/bin/Xvnc,
197 /usr/bin/Xephyr, /usr/bin/x11vnc, /usr/X11R6/bin/X, /usr/bin/Xway‐
198 land, /usr/X11R6/bin/Xorg, /usr/X11R6/bin/Xipaq,
199 /usr/libexec/Xorg.bin, /usr/X11R6/bin/XFree86,
200 /usr/libexec/Xorg.wrap, /usr/X11R6/bin/Xwrapper, /usr/libexec/gsd-
201 backlight-helper
202 xserver_log_t
205 - Set files with the xserver_log_t type, if you want to treat the data
207 as xserver log data, usually stored under the /var/log directory.
208 Paths:
211 /var/[xgkw]dm(/.*)?, /usr/var/[xgkw]dm(/.*)?,
212 /var/log/gdm(3)?(/.*)?, /var/log/Xorg.*, /var/log/XFree86.*,
213 /var/log/lightdm(/.*)?, /var/log/nvidia-installer.log.*
214 xserver_tmpfs_t
217 - Set files with the xserver_tmpfs_t type, if you want to store xserver
219 files on a tmpfs file system.
220 xserver_var_lib_t
224 - Set files with the xserver_var_lib_t type, if you want to store the
226 xserver files under the /var/lib directory.
227 xserver_var_run_t
231 - Set files with the xserver_var_run_t type, if you want to store the
233 xserver files under the /run or /var/run directory.
234 Paths:
237 /var/run/xorg(/.*)?, /var/run/video.rom
238 Note: File context can be temporarily modified with the chcon command.
241 If you want to permanently change the file context you need to use the
242 semanage fcontext command. This will modify the SELinux labeling data‐
243 base. You will need to use restorecon to apply the labels.
244
247 semanage fcontext can also be used to manipulate default file context
248 mappings.
249 semanage permissive can also be used to manipulate whether or not a
251 process type is permissive.
252 semanage module can also be used to enable/disable/install/remove pol‐
254 icy modules.
255 semanage port can also be used to manipulate the port definitions
257 semanage boolean can also be used to manipulate the booleans
259 system-config-selinux is a GUI tool available to customize SELinux pol‐
262 icy settings.
263
266 This manual page was auto-generated using sepolicy manpage .
267
270 selinux(8), xserver(8), semanage(8), restorecon(8), chcon(1), sepol‐
271 icy(8), setsebool(8)
272xserver 22-05-27 xserver_selinux(8)