linux + when change passwd we get permission denied

Question

We have installed Redhat Linux 6.5 from scratch the VIA kick start installation and booted into single user mode because I don't have the root password.

But when I perform the following:

passwd root
changing password for user root
passwd: permission denied

Please advice what are the reasons that I get permission denied and how to resolve the problem.

score 2 · Answer 1 · answered Apr 13 '16 at 11:33

2

you are in single user mode so you don't specify users

make sure your root filesystem is mounted in read/write

mount -o remount,rw /

then

passwd

answered Apr 13 '16 at 11:33

Sum1sAdmin

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I still get permission denied – dandan Apr 13 '16 at 12:07
does the prompt say root@host ? – Sum1sAdmin Apr 13 '16 at 12:08
yes I get root@linux_test – dandan Apr 13 '16 at 13:06
was this server joined to ldap? you may need to look into your /etc/nsswitch.conf in the meantime tell passwd you want to use the local possword file and not reset an ldap password, try: passwd -r files root – Sum1sAdmin Apr 13 '16 at 13:15
no - this server not joined to the ldap – dandan Apr 13 '16 at 13:16
passwd -r files root – Sum1sAdmin Apr 13 '16 at 13:17
when I run this I get passwd bad argument -r – dandan Apr 13 '16 at 13:19
I have redhat release 6.7 – dandan Apr 13 '16 at 13:20
were u able to fix the problem? I was curious – Koen van der Rijt Apr 14 '16 at 08:34
no still not I have the same problem – dandan Apr 14 '16 at 10:47

Koen van der Rijt · Answer 2 · 2016-04-13T13:13:34.300

this feels like an selinux issue with the files related to passwd. If something has changed the passwd files when selinux was not active it can have the wrong labels and selinux will deny access to the file. (You can probably confirm if selinux is on by examining the kickstart file)

Follow the instructions from here to boot into rescue mode.

After you gain access to the rescue enviroment perform the following instructions to force selinux to relabel the filesystem at next boot

# mount -o remount,rw /mnt/sysimage
# chroot /mnt/sysimage
# touch /.autorelabel
# reboot

Another approach: If you can boot into single user mode u can check if selinux is running.

# getenforce

this will can either say enforcing, permissive or disabled. You can then decide to disable it while you repair the damage. If you need to turn it off follow these instructions

vi /etc/sysconfig/selinux

Look for the line that says SELINUX=ENFORCING and replace ENFORCING with DISABLED. After that save/exit the file and reboot. If selinux was the culprit you should be able to login like normal.

linux + when change passwd we get permission denied

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