General Information
If you cannot perform this procedure, you will fail the entire exam.
Recover the root user's password
Interrupt boot process at grub menu (move an arrow key up or down to stop the grub boot countdown)
Press “e” to edit the grub menu entry
Navigate to the line starting with “linux16”; this is the kernel
Append to the end of the kernel entry (Ctrl+e to go to the end of the line)
rd.break enforcing=0
rd.break ⇒ stops early in the boot process (when initramfs is in memory and has not mounted the root file system as rw yet)
enforcing=0 ⇒ set SELinux to permissive mode
Ctrl+x to continue boot process, it will stop within the initramfs shell
Remount the sysroot file system as read/write
mount -o remount,rw /sysroot
Change root to that root file system
chroot /sysroot
Change root password
passwd
Exit the chroot jail and initramfs shell
sh-4.2# exit
switch_root:/# exit
The system will continue to boot
Note: There may be a considerable delay where it looks like nothing is happening, be patient.
Login as root with the new password
Restore SELinux file context to /etc/shadow
restorecon -v /etc/shadow
Set SELinux to enforcing again
setenforce 1