change shell of a user from /bin/false to another

Question

I made a mistake of change the root shell to /bin/false, but when I want to change it back, I always got error

sudo chsh -s /bin/bash root
[sudo] password: <input current user password>
password: <input root password>
chsh: PAM: Authentication failure

Answer 1

You can modify the file /etc/passwd if chsh doesn't work, by replacing the line

root:x:0:0:root:/root:/bin/false

with

root:x:0:0:root:/root:/bin/bash

Answer 2

Try:

sudo vigr

In the editor, change root's shell back to /bin/bash (It should be the last field on the first line)