Change the root password

Question

I have used this procedure to change the root password:

1. Get to GRUB screen
2. Press e to edit
3. add rw init=/bin/bash to end of the kernel line
4. ctrl-x to reboot
5. from there I would mount -rw -o remount / then passwd, etc...

That has worked in the past. This time I get:

bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
root@(none):/#

Then nothing. No response to any keyboard entry.

I also tried to boot to the recovery mode but when I hit to "Drop to root shell prompt", it shows me the message:

Give root password for maintenance (or type Control-D to continue)