prelink_selinux(8)

1prelink_selinux(8)          SELinux Policy prelink          prelink_selinux(8)
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NAME

6       prelink_selinux  -  Security Enhanced Linux Policy for the prelink pro‐
7       cesses
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DESCRIPTION

10       Security-Enhanced Linux secures  the  prelink  processes  via  flexible
11       mandatory access control.
12
13       The  prelink processes execute with the prelink_t SELinux type. You can
14       check if you have these processes running by executing the  ps  command
15       with the -Z qualifier.
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17       For example:
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19       ps -eZ | grep prelink_t
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ENTRYPOINTS

24       The  prelink_t  SELinux type can be entered via the prelink_exec_t file
25       type.
26
27       The default entrypoint paths for the prelink_t domain are  the  follow‐
28       ing:
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30       /usr/sbin/prelink(.bin)?
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PROCESS TYPES

33       SELinux defines process types (domains) for each process running on the
34       system
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36       You can see the context of a process using the -Z option to ps
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38       Policy governs the access confined processes have  to  files.   SELinux
39       prelink  policy  is very flexible allowing users to setup their prelink
40       processes in as secure a method as possible.
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42       The following process types are defined for prelink:
43
44       prelink_t, prelink_cron_system_t
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46       Note: semanage permissive -a prelink_t can be used to make the  process
47       type  prelink_t  permissive. SELinux does not deny access to permissive
48       process types, but the AVC (SELinux denials) messages are still  gener‐
49       ated.
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51

BOOLEANS

53       SELinux policy is customizable based on least access required.  prelink
54       policy is extremely flexible and has several booleans that allow you to
55       manipulate  the  policy and run prelink with the tightest access possi‐
56       ble.
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59
60       If you want to allow all daemons the ability to  read/write  terminals,
61       you must turn on the daemons_use_tty boolean. Disabled by default.
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63       setsebool -P daemons_use_tty 1
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67       If you want to deny user domains applications to map a memory region as
68       both executable and writable, this  is  dangerous  and  the  executable
69       should be reported in bugzilla, you must turn on the deny_execmem bool‐
70       ean. Enabled by default.
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72       setsebool -P deny_execmem 1
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76       If you want to deny any process from ptracing or  debugging  any  other
77       processes,  you  must  turn  on  the  deny_ptrace  boolean.  Enabled by
78       default.
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80       setsebool -P deny_ptrace 1
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84       If you want to allow any process  to  mmap  any  file  on  system  with
85       attribute  file_type,  you must turn on the domain_can_mmap_files bool‐
86       ean. Enabled by default.
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88       setsebool -P domain_can_mmap_files 1
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92       If you want to allow all domains write to kmsg_device, while kernel  is
93       executed  with  systemd.log_target=kmsg parameter, you must turn on the
94       domain_can_write_kmsg boolean. Disabled by default.
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96       setsebool -P domain_can_write_kmsg 1
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100       If you want to allow all domains to use other domains file descriptors,
101       you must turn on the domain_fd_use boolean. Enabled by default.
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103       setsebool -P domain_fd_use 1
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107       If  you  want to allow all domains to have the kernel load modules, you
108       must  turn  on  the  domain_kernel_load_modules  boolean.  Disabled  by
109       default.
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111       setsebool -P domain_kernel_load_modules 1
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114
115       If you want to allow all domains to execute in fips_mode, you must turn
116       on the fips_mode boolean. Enabled by default.
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118       setsebool -P fips_mode 1
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121
122       If you want to enable reading of urandom for all domains, you must turn
123       on the global_ssp boolean. Disabled by default.
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125       setsebool -P global_ssp 1
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129       If  you  want  to control the ability to mmap a low area of the address
130       space, as configured by /proc/sys/vm/mmap_min_addr, you  must  turn  on
131       the mmap_low_allowed boolean. Disabled by default.
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133       setsebool -P mmap_low_allowed 1
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137       If  you  want  to  disable  kernel module loading, you must turn on the
138       secure_mode_insmod boolean. Enabled by default.
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140       setsebool -P secure_mode_insmod 1
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143
144       If you want to boolean to determine whether the system permits  loading
145       policy,  setting enforcing mode, and changing boolean values.  Set this
146       to true and you have to reboot to set it back, you  must  turn  on  the
147       secure_mode_policyload boolean. Enabled by default.
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149       setsebool -P secure_mode_policyload 1
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152
153       If  you  want to allow unconfined executables to make their heap memory
154       executable.  Doing this is a really  bad  idea.  Probably  indicates  a
155       badly  coded  executable, but could indicate an attack. This executable
156       should  be  reported  in  bugzilla,  you  must  turn  on   the   selin‐
157       uxuser_execheap boolean. Disabled by default.
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159       setsebool -P selinuxuser_execheap 1
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163       If  you  want  to  allow  all  unconfined  executables to use libraries
164       requiring text relocation that are  not  labeled  textrel_shlib_t,  you
165       must turn on the selinuxuser_execmod boolean. Enabled by default.
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167       setsebool -P selinuxuser_execmod 1
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171       If  you  want  to allow unconfined executables to make their stack exe‐
172       cutable.  This should never, ever be necessary.  Probably  indicates  a
173       badly  coded  executable, but could indicate an attack. This executable
174       should be reported in bugzilla, you must turn on the  selinuxuser_exec‐
175       stack boolean. Enabled by default.
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177       setsebool -P selinuxuser_execstack 1
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180
181       If you want to support X userspace object manager, you must turn on the
182       xserver_object_manager boolean. Enabled by default.
183
184       setsebool -P xserver_object_manager 1
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MANAGED FILES

189       The SELinux process type prelink_t can manage files  labeled  with  the
190       following file types.  The paths listed are the default paths for these
191       file types.  Note the processes UID still need to have DAC permissions.
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193       file_type
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195            all files on the system
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197

FILE CONTEXTS

199       SELinux requires files to have an extended attribute to define the file
200       type.
201
202       You can see the context of a file using the -Z option to ls
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204       Policy  governs  the  access  confined  processes  have to these files.
205       SELinux prelink policy is very flexible allowing users to  setup  their
206       prelink processes in as secure a method as possible.
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208       EQUIVALENCE DIRECTORIES
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211       prelink  policy  stores data with multiple different file context types
212       under the /var/log/prelink directory.  If you would like to  store  the
213       data  in a different directory you can use the semanage command to cre‐
214       ate an equivalence mapping.  If you wanted to store this data under the
215       /srv dirctory you would execute the following command:
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217       semanage fcontext -a -e /var/log/prelink /srv/prelink
218       restorecon -R -v /srv/prelink
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220       STANDARD FILE CONTEXT
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222       SELinux  defines  the file context types for the prelink, if you wanted
223       to store files with these types in a diffent paths, you need to execute
224       the  semanage  command  to  sepecify  alternate  labeling  and then use
225       restorecon to put the labels on disk.
226
227       semanage  fcontext   -a   -t   prelink_var_lib_t   '/srv/myprelink_con‐
228       tent(/.*)?'
229       restorecon -R -v /srv/myprelink_content
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231       Note:  SELinux  often  uses  regular expressions to specify labels that
232       match multiple files.
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234       The following file types are defined for prelink:
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238       prelink_cache_t
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240       - Set files with the prelink_cache_t type, if you  want  to  store  the
241       files under the /var/cache directory.
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245       prelink_cron_system_exec_t
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247       -  Set  files  with the prelink_cron_system_exec_t type, if you want to
248       transition an executable to the prelink_cron_system_t domain.
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252       prelink_exec_t
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254       - Set files with the prelink_exec_t type, if you want to transition  an
255       executable to the prelink_t domain.
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259       prelink_log_t
260
261       -  Set files with the prelink_log_t type, if you want to treat the data
262       as prelink log data, usually stored under the /var/log directory.
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264
265       Paths:
266            /var/log/prelink(/.*)?, /var/log/prelink.log.*
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268
269       prelink_tmp_t
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271       - Set files with the prelink_tmp_t type, if you want to  store  prelink
272       temporary files in the /tmp directories.
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276       prelink_tmpfs_t
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278       - Set files with the prelink_tmpfs_t type, if you want to store prelink
279       files on a tmpfs file system.
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283       prelink_var_lib_t
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285       - Set files with the prelink_var_lib_t type, if you want to  store  the
286       prelink files under the /var/lib directory.
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289       Paths:
290            /var/lib/prelink(/.*)?, /var/lib/misc/prelink.*
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292
293       Note:  File context can be temporarily modified with the chcon command.
294       If you want to permanently change the file context you need to use  the
295       semanage fcontext command.  This will modify the SELinux labeling data‐
296       base.  You will need to use restorecon to apply the labels.
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298

COMMANDS

300       semanage fcontext can also be used to manipulate default  file  context
301       mappings.
302
303       semanage  permissive  can  also  be used to manipulate whether or not a
304       process type is permissive.
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306       semanage module can also be used to enable/disable/install/remove  pol‐
307       icy modules.
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309       semanage boolean can also be used to manipulate the booleans
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311
312       system-config-selinux is a GUI tool available to customize SELinux pol‐
313       icy settings.
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AUTHOR

317       This manual page was auto-generated using sepolicy manpage .
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