Provided by: selinux-utils_2.4-3build2_i386 bug


       SELinux - NSA Security-Enhanced Linux (SELinux)


       NSA  Security-Enhanced  Linux  (SELinux)  is  an  implementation  of  a
       flexible mandatory access control architecture in the  Linux  operating
       system.   The  SELinux  architecture  provides  general support for the
       enforcement  of  many  kinds  of  mandatory  access  control  policies,
       including those based on the concepts of Type EnforcementĀ®, Role- Based
       Access Control, and Multi-Level Security.  Background  information  and
       technical    documentation    about    SELinux    can   be   found   at

       The /etc/selinux/config configuration file controls whether SELinux  is
       enabled  or  disabled,  and  if  enabled,  whether  SELinux operates in
       permissive mode or enforcing mode.  The SELINUX variable may be set  to
       any  one  of  disabled, permissive, or enforcing to select one of these
       options.  The disabled option completely disables  the  SELinux  kernel
       and  application  code,  leaving the system running without any SELinux
       protection.  The permissive option enables the SELinux code, but causes
       it  to  operate in a mode where accesses that would be denied by policy
       are permitted but audited.  The enforcing option  enables  the  SELinux
       code  and causes it to enforce access denials as well as auditing them.
       Permissive mode may yield a different set  of  denials  than  enforcing
       mode,  both  because  enforcing  mode  will  prevent  an operation from
       proceeding past the first denial and because some application code will
       fall back to a less privileged mode of operation if denied access.

       The /etc/selinux/config configuration file also controls what policy is
       active on the system.  SELinux  allows  for  multiple  policies  to  be
       installed on the system, but only one policy may be active at any given
       time.  At present, multiple kinds of SELinux  policy  exist:  targeted,
       mls  for  example.   The  targeted policy is designed as a policy where
       most user processes operate without  restrictions,  and  only  specific
       services are placed into distinct security domains that are confined by
       the policy.  For example, the user would run in a completely unconfined
       domain  while the named daemon or apache daemon would run in a specific
       domain tailored to  its  operation.   The  MLS  (Multi-Level  Security)
       policy is designed as a policy where all processes are partitioned into
       fine-grained  security  domains  and  confined  by  policy.   MLS  also
       supports  the  Bell  And  LaPadula  model, where processes are not only
       confined by the type but also the level of the data.

       You can define which policy you will run  by  setting  the  SELINUXTYPE
       environment  variable  within /etc/selinux/config.  You must reboot and
       possibly relabel if you change the policy type to have it  take  effect
       on  the  system.   The corresponding policy configuration for each such
       policy   must   be   installed   in   the   /etc/selinux/{SELINUXTYPE}/

       A  given  SELinux  policy  can  be customized further based on a set of
       compile-time tunable options and a  set  of  runtime  policy  booleans.
       system-config-selinux   allows  customization  of  these  booleans  and

       Many domains that are protected by SELinux  also  include  SELinux  man
       pages explaining how to customize their policy.


       All  files,  directories,  devices  ...  have  a security context/label
       associated with  them.   These  context  are  stored  in  the  extended
       attributes  of the file system.  Problems with SELinux often arise from
       the file system being mislabeled. This can be  caused  by  booting  the
       machine  with  a  non  SELinux  kernel.   If  you  see an error message
       containing file_t, that is usually a good indicator  that  you  have  a
       serious problem with file system labeling.

       The  best  way  to  relabel  the file system is to create the flag file
       /.autorelabel  and  reboot.   system-config-selinux,  also   has   this
       capability.   The  restorecon/fixfiles  commands are also available for
       relabeling files.


       This manual page was written by Dan Walsh <>.




       booleans(8), setsebool(8), sepolicy(8), system-config-selinux(8),
       togglesebool(8), restorecon(8), fixfiles(8), setfiles(8), semanage(8),

       Every confined service on the system has a man page in the following


       For example, httpd has the httpd_selinux(8) man page.

       man -k selinux

       Will list all SELinux man pages.