kernel_selinux(8)

1kernel_selinux(8)            SELinux Policy kernel           kernel_selinux(8)
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NAME

6       kernel_selinux  -  Security  Enhanced  Linux Policy for the kernel pro‐
7       cesses
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DESCRIPTION

10       Security-Enhanced Linux  secures  the  kernel  processes  via  flexible
11       mandatory access control.
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13       The  kernel  processes  execute with the kernel_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 kernel_t
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PROCESS TYPES

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

44       SELinux  policy is customizable based on least access required.  kernel
45       policy is extremely flexible and has several booleans that allow you to
46       manipulate the policy and run kernel with the tightest access possible.
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50       If you want to deny user domains applications to map a memory region as
51       both executable and writable, this  is  dangerous  and  the  executable
52       should be reported in bugzilla, you must turn on the deny_execmem bool‐
53       ean. Enabled by default.
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55       setsebool -P deny_execmem 1
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59       If you want to deny any process from ptracing or  debugging  any  other
60       processes,  you  must  turn  on  the  deny_ptrace  boolean.  Enabled by
61       default.
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63       setsebool -P deny_ptrace 1
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67       If you want to allow any process  to  mmap  any  file  on  system  with
68       attribute  file_type,  you must turn on the domain_can_mmap_files bool‐
69       ean. Enabled by default.
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71       setsebool -P domain_can_mmap_files 1
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75       If you want to allow all domains write to kmsg_device, while kernel  is
76       executed  with  systemd.log_target=kmsg parameter, you must turn on the
77       domain_can_write_kmsg boolean. Disabled by default.
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79       setsebool -P domain_can_write_kmsg 1
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83       If you want to allow all domains to use other domains file descriptors,
84       you must turn on the domain_fd_use boolean. Enabled by default.
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86       setsebool -P domain_fd_use 1
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90       If  you  want to allow all domains to have the kernel load modules, you
91       must  turn  on  the  domain_kernel_load_modules  boolean.  Disabled  by
92       default.
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94       setsebool -P domain_kernel_load_modules 1
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98       If you want to allow all domains to execute in fips_mode, you must turn
99       on the fips_mode boolean. Enabled by default.
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101       setsebool -P fips_mode 1
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105       If you want to enable reading of urandom for all domains, you must turn
106       on the global_ssp boolean. Disabled by default.
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108       setsebool -P global_ssp 1
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112       If  you  want  to control the ability to mmap a low area of the address
113       space, as configured by /proc/sys/vm/mmap_min_addr, you  must  turn  on
114       the mmap_low_allowed boolean. Disabled by default.
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116       setsebool -P mmap_low_allowed 1
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120       If you want to allow any files/directories to be exported read/only via
121       NFS, you  must  turn  on  the  nfs_export_all_ro  boolean.  Enabled  by
122       default.
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124       setsebool -P nfs_export_all_ro 1
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128       If  you  want  to allow any files/directories to be exported read/write
129       via NFS, you must turn on the  nfs_export_all_rw  boolean.  Enabled  by
130       default.
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132       setsebool -P nfs_export_all_rw 1
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136       If  you  want  to  allow  system  to run with NIS, you must turn on the
137       nis_enabled boolean. Disabled by default.
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139       setsebool -P nis_enabled 1
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143       If you want to disable kernel module loading,  you  must  turn  on  the
144       secure_mode_insmod boolean. Enabled by default.
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146       setsebool -P secure_mode_insmod 1
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150       If  you want to boolean to determine whether the system permits loading
151       policy, setting enforcing mode, and changing boolean values.  Set  this
152       to  true  and  you  have to reboot to set it back, you must turn on the
153       secure_mode_policyload boolean. Enabled by default.
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155       setsebool -P secure_mode_policyload 1
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159       If you want to allow unconfined executables to make their  heap  memory
160       executable.   Doing  this  is  a  really bad idea. Probably indicates a
161       badly coded executable, but could indicate an attack.  This  executable
162       should   be   reported  in  bugzilla,  you  must  turn  on  the  selin‐
163       uxuser_execheap boolean. Disabled by default.
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165       setsebool -P selinuxuser_execheap 1
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169       If you want to  allow  all  unconfined  executables  to  use  libraries
170       requiring  text  relocation  that  are not labeled textrel_shlib_t, you
171       must turn on the selinuxuser_execmod boolean. Enabled by default.
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173       setsebool -P selinuxuser_execmod 1
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177       If you want to allow unconfined executables to make  their  stack  exe‐
178       cutable.   This  should  never, ever be necessary. Probably indicates a
179       badly coded executable, but could indicate an attack.  This  executable
180       should  be reported in bugzilla, you must turn on the selinuxuser_exec‐
181       stack boolean. Enabled by default.
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183       setsebool -P selinuxuser_execstack 1
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187       If you want to support X userspace object manager, you must turn on the
188       xserver_object_manager boolean. Enabled by default.
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190       setsebool -P xserver_object_manager 1
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MANAGED FILES

195       The  SELinux  process  type  kernel_t can manage files labeled with the
196       following file types.  The paths listed are the default paths for these
197       file types.  Note the processes UID still need to have DAC permissions.
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199       file_type
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201            all files on the system
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COMMANDS

205       semanage  fcontext  can also be used to manipulate default file context
206       mappings.
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208       semanage permissive can also be used to manipulate  whether  or  not  a
209       process type is permissive.
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211       semanage  module can also be used to enable/disable/install/remove pol‐
212       icy modules.
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214       semanage boolean can also be used to manipulate the booleans
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217       system-config-selinux is a GUI tool available to customize SELinux pol‐
218       icy settings.
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AUTHOR

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