crond_selinux(8)

1crond_selinux(8)             SELinux Policy crond             crond_selinux(8)
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NAME

6       crond_selinux - Security Enhanced Linux Policy for the crond processes
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DESCRIPTION

9       Security-Enhanced Linux secures the crond processes via flexible manda‐
10       tory access control.
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12       The crond processes execute with the  crond_t  SELinux  type.  You  can
13       check  if  you have these processes running by executing the ps command
14       with the -Z qualifier.
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16       For example:
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18       ps -eZ | grep crond_t
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ENTRYPOINTS

23       The crond_t SELinux type can be entered via the crond_exec_t file type.
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25       The default entrypoint paths for the crond_t domain are the following:
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27       /usr/sbin/cron(d)?, /usr/sbin/atd, /usr/sbin/fcron, /usr/libexec/fcron
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PROCESS TYPES

30       SELinux defines process types (domains) for each process running on the
31       system
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33       You can see the context of a process using the -Z option to ps
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35       Policy  governs  the  access confined processes have to files.  SELinux
36       crond policy is very flexible allowing users to setup their crond  pro‐
37       cesses in as secure a method as possible.
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39       The following process types are defined for crond:
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41       crond_t
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43       Note:  semanage  permissive  -a crond_t can be used to make the process
44       type crond_t permissive. SELinux does not  deny  access  to  permissive
45       process  types, but the AVC (SELinux denials) messages are still gener‐
46       ated.
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BOOLEANS

50       SELinux policy is customizable based on least access  required.   crond
51       policy is extremely flexible and has several booleans that allow you to
52       manipulate the policy and run crond with the tightest access possible.
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56       If you want to determine whether crond can execute jobs in the user do‐
57       main as opposed to the the generic cronjob domain, you must turn on the
58       cron_userdomain_transition boolean. Enabled by default.
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60       setsebool -P cron_userdomain_transition 1
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64       If you want to dontaudit all  daemons  scheduling  requests  (setsched,
65       sys_nice),  you  must turn on the daemons_dontaudit_scheduling boolean.
66       Enabled by default.
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68       setsebool -P daemons_dontaudit_scheduling 1
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72       If you want to deny user domains applications to map a memory region as
73       both  executable  and  writable,  this  is dangerous and the executable
74       should be reported in bugzilla, you must turn on the deny_execmem bool‐
75       ean. Disabled by default.
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77       setsebool -P deny_execmem 1
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81       If  you  want  to control the ability to mmap a low area of the address
82       space, as configured by /proc/sys/vm/mmap_min_addr, you  must  turn  on
83       the mmap_low_allowed boolean. Disabled by default.
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85       setsebool -P mmap_low_allowed 1
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89       If  you  want  to  allow  system  to run with NIS, you must turn on the
90       nis_enabled boolean. Disabled by default.
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92       setsebool -P nis_enabled 1
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96       If you want to enable polyinstantiated directory support, you must turn
97       on the polyinstantiation_enabled boolean. Disabled by default.
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99       setsebool -P polyinstantiation_enabled 1
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103       If  you want to disable kernel module loading, you must turn on the se‐
104       cure_mode_insmod boolean. Disabled by default.
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106       setsebool -P secure_mode_insmod 1
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110       If you want to allow unconfined executables to make their  heap  memory
111       executable.   Doing  this  is  a  really bad idea. Probably indicates a
112       badly coded executable, but could indicate an attack.  This  executable
113       should  be  reported  in bugzilla, you must turn on the selinuxuser_ex‐
114       echeap boolean. Disabled by default.
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116       setsebool -P selinuxuser_execheap 1
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119
120       If you want to allow unconfined executables to make  their  stack  exe‐
121       cutable.   This  should  never, ever be necessary. Probably indicates a
122       badly coded executable, but could indicate an attack.  This  executable
123       should  be reported in bugzilla, you must turn on the selinuxuser_exec‐
124       stack boolean. Enabled by default.
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126       setsebool -P selinuxuser_execstack 1
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MANAGED FILES

131       The SELinux process type crond_t can manage files labeled with the fol‐
132       lowing  file  types.   The paths listed are the default paths for these
133       file types.  Note the processes UID still need to have DAC permissions.
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135       file_type
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137            all files on the system
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FILE CONTEXTS

141       SELinux requires files to have an extended attribute to define the file
142       type.
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144       You can see the context of a file using the -Z option to ls
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146       Policy  governs  the  access  confined  processes  have to these files.
147       SELinux crond policy is very flexible allowing  users  to  setup  their
148       crond processes in as secure a method as possible.
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150       STANDARD FILE CONTEXT
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152       SELinux  defines the file context types for the crond, if you wanted to
153       store files with these types in a different paths, you need to  execute
154       the  semanage  command  to  specify alternate labeling and then use re‐
155       storecon to put the labels on disk.
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157       semanage fcontext -a -t crond_exec_t '/srv/crond/content(/.*)?'
158       restorecon -R -v /srv/mycrond_content
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160       Note: SELinux often uses regular expressions  to  specify  labels  that
161       match multiple files.
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163       The following file types are defined for crond:
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167       crond_exec_t
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169       -  Set  files  with the crond_exec_t type, if you want to transition an
170       executable to the crond_t domain.
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173       Paths:
174            /usr/sbin/cron(d)?,        /usr/sbin/atd,         /usr/sbin/fcron,
175            /usr/libexec/fcron
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178       crond_initrc_exec_t
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180       -  Set  files with the crond_initrc_exec_t type, if you want to transi‐
181       tion an executable to the crond_initrc_t domain.
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185       crond_tmp_t
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187       - Set files with the crond_tmp_t type, if you want to store crond  tem‐
188       porary files in the /tmp directories.
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192       crond_unit_file_t
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194       -  Set  files with the crond_unit_file_t type, if you want to treat the
195       files as crond unit content.
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198       Paths:
199            /usr/lib/systemd/system/atd.*, /usr/lib/systemd/system/crond.*
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202       crond_var_run_t
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204       - Set files with the crond_var_run_t type, if you  want  to  store  the
205       crond files under the /run or /var/run directory.
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208       Paths:
209            /var/run/.*cron.*,   /var/run/crond?.pid,  /var/run/crond?.reboot,
210            /var/run/atd.pid,     /var/run/fcron.pid,     /var/run/fcron.fifo,
211            /var/run/anacron.pid
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213
214       Note:  File context can be temporarily modified with the chcon command.
215       If you want to permanently change the file context you need to use  the
216       semanage fcontext command.  This will modify the SELinux labeling data‐
217       base.  You will need to use restorecon to apply the labels.
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COMMANDS

221       semanage fcontext can also be used to manipulate default  file  context
222       mappings.
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224       semanage  permissive  can  also  be used to manipulate whether or not a
225       process type is permissive.
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227       semanage module can also be used to enable/disable/install/remove  pol‐
228       icy modules.
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230       semanage boolean can also be used to manipulate the booleans
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233       system-config-selinux is a GUI tool available to customize SELinux pol‐
234       icy settings.
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AUTHOR

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