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<title>kernel_selinux</title>
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<h1 align="center">kernel_selinux</h1>
<a href="#NAME">NAME</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#PROCESS TYPES">PROCESS TYPES</a><br>
<a href="#BOOLEANS">BOOLEANS</a><br>
<a href="#MANAGED FILES">MANAGED FILES</a><br>
<a href="#COMMANDS">COMMANDS</a><br>
<a href="#AUTHOR">AUTHOR</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<hr>
<h2>NAME
<a name="NAME"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">kernel_selinux
− Security Enhanced Linux Policy for the kernel
processes</p>
<h2>DESCRIPTION
<a name="DESCRIPTION"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">Security-Enhanced
Linux secures the kernel processes via flexible mandatory
access control.</p>
<p style="margin-left:11%; margin-top: 1em">The kernel
processes execute with the kernel_t SELinux type. You can
check if you have these processes running by executing the
<b>ps</b> command with the <b>−Z</b> qualifier.</p>
<p style="margin-left:11%; margin-top: 1em">For
example:</p>
<p style="margin-left:11%; margin-top: 1em"><b>ps -eZ |
grep kernel_t</b></p>
<h2>PROCESS TYPES
<a name="PROCESS TYPES"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">SELinux defines
process types (domains) for each process running on the
system</p>
<p style="margin-left:11%; margin-top: 1em">You can see the
context of a process using the <b>−Z</b> option to
<b>ps</b></p>
<p style="margin-left:11%; margin-top: 1em">Policy governs
the access confined processes have to files. SELinux kernel
policy is very flexible allowing users to setup their kernel
processes in as secure a method as possible.</p>
<p style="margin-left:11%; margin-top: 1em">The following
process types are defined for kernel:</p>
<p style="margin-left:11%; margin-top: 1em"><b>kernel_t</b></p>
<p style="margin-left:11%; margin-top: 1em">Note:
<b>semanage permissive -a kernel_t</b> can be used to make
the process type kernel_t permissive. SELinux does not deny
access to permissive process types, but the AVC (SELinux
denials) messages are still generated.</p>
<h2>BOOLEANS
<a name="BOOLEANS"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">SELinux policy
is customizable based on least access required. kernel
policy is extremely flexible and has several booleans that
allow you to manipulate the policy and run kernel with the
tightest access possible.</p>
<p style="margin-left:11%; margin-top: 1em">If you want to
deny user domains applications to map a memory region as
both executable and writable, this is dangerous and the
executable should be reported in bugzilla, you must turn on
the deny_execmem boolean. Disabled by default.</p>
<p style="margin-left:11%; margin-top: 1em"><b>setsebool -P
deny_execmem 1</b></p>
<p style="margin-left:11%; margin-top: 1em">If you want to
control the ability to mmap a low area of the address space,
as configured by /proc/sys/vm/mmap_min_addr, you must turn
on the mmap_low_allowed boolean. Disabled by default.</p>
<p style="margin-left:11%; margin-top: 1em"><b>setsebool -P
mmap_low_allowed 1</b></p>
<p style="margin-left:11%; margin-top: 1em">If you want to
allow system to run with NIS, you must turn on the
nis_enabled boolean. Disabled by default.</p>
<p style="margin-left:11%; margin-top: 1em"><b>setsebool -P
nis_enabled 1</b></p>
<p style="margin-left:11%; margin-top: 1em">If you want to
disable kernel module loading, you must turn on the
secure_mode_insmod boolean. Disabled by default.</p>
<p style="margin-left:11%; margin-top: 1em"><b>setsebool -P
secure_mode_insmod 1</b></p>
<p style="margin-left:11%; margin-top: 1em">If you want to
allow unconfined executables to make their heap memory
executable. Doing this is a really bad idea. Probably
indicates a badly coded executable, but could indicate an
attack. This executable should be reported in bugzilla, you
must turn on the selinuxuser_execheap boolean. Disabled by
default.</p>
<p style="margin-left:11%; margin-top: 1em"><b>setsebool -P
selinuxuser_execheap 1</b></p>
<p style="margin-left:11%; margin-top: 1em">If you want to
allow unconfined executables to make their stack executable.
This should never, ever be necessary. Probably indicates a
badly coded executable, but could indicate an attack. This
executable should be reported in bugzilla, you must turn on
the selinuxuser_execstack boolean. Enabled by default.</p>
<p style="margin-left:11%; margin-top: 1em"><b>setsebool -P
selinuxuser_execstack 1</b></p>
<h2>MANAGED FILES
<a name="MANAGED FILES"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">The SELinux
process type kernel_t can manage files labeled with the
following file types. The paths listed are the default paths
for these file types. Note the processes UID still need to
have DAC permissions.</p>
<p style="margin-left:11%; margin-top: 1em"><b>file_type</b></p>
<p style="margin-left:11%; margin-top: 1em">all files on
the system</p>
<h2>COMMANDS
<a name="COMMANDS"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>semanage
fcontext</b> can also be used to manipulate default file
context mappings.</p>
<p style="margin-left:11%; margin-top: 1em"><b>semanage
permissive</b> can also be used to manipulate whether or not
a process type is permissive.</p>
<p style="margin-left:11%; margin-top: 1em"><b>semanage
module</b> can also be used to enable/disable/install/remove
policy modules.</p>
<p style="margin-left:11%; margin-top: 1em"><b>semanage
boolean</b> can also be used to manipulate the booleans</p>
<p style="margin-left:11%; margin-top: 1em"><b>system-config-selinux</b>
is a GUI tool available to customize SELinux policy
settings.</p>
<h2>AUTHOR
<a name="AUTHOR"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">This manual
page was auto-generated using <b>sepolicy manpage .</b></p>
<h2>SEE ALSO
<a name="SEE ALSO"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">selinux(8),
kernel(8), semanage(8), restorecon(8), chcon(1),
sepolicy(8), setsebool(8)</p>
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