i’m new to CentOS and trying to enable SELinux and it’s not working after a restart as described on https://www.digitalocean.com/community/tutorials/an-introduction-to-selinux-on-centos-7-part-1-basic-concepts.
The only error message I get after each reboot is:
master:~# cat /var/log/messages | grep "SELinux" Jul 14 22:11:48 master kernel: SELinux: Disabled at boot.
As far as Google could tell me this means my config file has SELINUX=0 / SELINUX=disabled. But my config file should be correct:
master:~# cat /etc/selinux/config # 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=permissive # SELINUXTYPE= can take one of three two values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted
I found it strange that the described /etc/sysconfig/selinux symlink did not exist so it created it pointing to /etc/selinux/config:
master:~# ls -l /etc/sysconfig/ | grep selinux lrwxrwxrwx 1 root root 19 Jul 14 22:18 selinux -> /etc/selinux/config
System Details: freshly installed minimal CentOS 7 with current updates:
master:~# uname -a Linux master 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 11:36:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
I also installed the packages described at the above link:
yum install policycoreutils policycoreutils-python selinux-policy selinux-policy-targeted libselinux-utils setroubleshoot-server setools setools-console mcstrans
Any idea how to debug this? I could not find any other way to enable SELinux other than changing the config file and rebooting, what could be wrong?
Could a kernel module be missing?
master:~# cat /etc/sysconfig/grub GRUB_TIMEOUT=5 GRUB_DEFAULT="" GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="rootflags=uquota,gquota acpi=ht crashkernel=auto selinux=0 nodmraid rhgb quiet" GRUB_DISABLE_RECOVERY="true"
SELinux was disabled on your kernel command line, by someone inserting
To resolve the problem, remove this from
/etc/sysconfig/grub, regenerate your grub configuration, and then reboot.
You should also complain to whoever made this image, as this is a really nasty trick to play…
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.