RH134 - ch07s03

For troubleshooting purposes, SELinux protection can be temporarily disabled using SELinux modes. This section will look at how to change SELinux modes temporarily between enforcing and permissive mode. It will also look at how to set the default SELinux mode that is determined at boot time.

Changing the current SELinux mode

SELinux modes

The setenforce command modifies the current SELinux mode:

[root@serverX ~]# getenforce
Enforcing
[root@serverX ~]# setenforce
usage:  setenforce [ Enforcing | Permissive | 1 | 0 ]
[root@serverX ~]# setenforce 0
[root@serverX ~]# getenforce
Permissive
[root@serverX ~]# setenforce Enforcing
[root@serverX ~]# getenforce
Enforcing

Another way to temporarily set the SELinux mode is to pass a parameter to the kernel at boot time. Passing a kernel argument of enforcing=0 causes the system to boot into permissive mode. A value of 1 would specify enforcing mode. SELinux can be disabled when the selinux=0 argument is specified. A value of 1 would enable SELinux.

Setting the default SELinux mode

The configuration file that determines what the SELinux mode is at boot time is /etc/selinux/config. Notice that it contains some useful comments:

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes
#               are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

Use /etc/selinux/config to change the default SELinux mode at boot time. In the example shown, it is set to enforcing mode.

Passing the selinux= and/or the enforcing= kernel arguments overrides any of the default values specified in /etc/selinux/config.

References

getenforce(1), setenforce(1), and selinux_config(5) man pages

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Is It possible to reset root password when the system is on multi-user.target?

jennifer1987

27 lip 2023

Hi thereWell, i have a question, Is It possible to reset root password when the system is on multi-user.target? I was not be able to found a foro o some information related with this and another question that I have, If the grub menu dont show up, is it posible to reset the root password?

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Red Hat System Administration II (RH134)

Haley_Ruccio

21 lip 2023

Build the skills to perform the key tasks needed to become a full-time Linux administratorRed Hat System Administration II (RH134) is the second part of the RHCSA training track for IT professionals who have already attended Red Hat System Administration I. The course goes deeper into core Linux system administration skills in storage configuration and management, installation and deployment of Red Hat Enterprise Linux, management of security features such as SELinux, control of recurring system tasks, management of the boot process and troubleshooting, basic system tuning, and command-line automation and productivity. This course assumes that students have attended Red Hat System Administration I (RH124).Experienced Linux administrators who seek rapid preparation for the RHCSA certification should instead start with RHCSA Rapid Track (RH199).This course is based on Red Hat Enterprise Linux 9.0.Course summaryInstall Red Hat Enterprise Linux using scalable methodsAccess security files, file systems, and networksExecute shell scripting and automation techniquesManage storage devices, logical volumes, and file systemsManage security and system accessControl the boot process and system servicesRun containersAudience for this courseThis course is geared toward Windows system administrators, network administrators, and other system administrators who are interested in supplementing current skills or backstopping other team members, in addition to Linux system administrators who are responsible for these tasks:Configuring, installing, upgrading, and maintaining Linux systems using established standards and proceduresProviding operational supportManaging systems for monitoring system performance and availabilityWriting and deploying scripts for task automation and system administrationRecommended trainingSuccessful completion of Red Hat System Administration I (RH124) is recommended.Experienced Linux administrators seeking to accelerate their path toward becoming a Red Hat Certified System Administrator should start with the RHCSA Rapid Track course (RH199).Take our free assessment to gauge whether this offering is the best fit for your skills.Technology considerationsThere are no special technology requirements.This course is not designed for bring your own device (BYOD).Internet access is not required, but is recommended to allow students to research and access Red Hat online resources.

Welcome to the Red Hat System Administration II (RH134) group in the Red Hat Learning Community!

Deanna

18 lip 2023

We are excited to launch a space dedicated to the Red Hat Training course Red Hat System Administration II! To gain the most value from this group - click the "Join Group" button in the upper right hand corner.We encourage group members to collaborate in this group to discuss topics, ask questions, share best practices and tips, provide course feedback, and share their accomplishments as it relates to RH134.Read more about Red Hat System Administration II here.

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Revision: rh134-7-63a207e