Reboot command says User root is logged in on sshd
Today I logged into to my linode machine through SSH as normal user.
I wanted to reboot my machine. So I ran reboot command. I got scared by looking at the output. It says
$ reboot
User root is logged in on sshd.
Please retry operation after closing inhibitors and logging out other users.
Alternatively, ignore inhibitors and users with 'systemctl reboot -i'.
Does this mean there is someone who logged in as root through SSH?
I have not logged into machine as root user through SSH.
Is my machine hacked???
In SSH, root login is allowed with password.
Someone please explain what's happening…
9 Replies
It means that a non-root user cannot reboot the system. Also I would disable the root account from being able to login via SSH. It's a huge security hole.
Best to reboot via the Linode dashboard. That is how I've always done it and never had an issue.
@acanton77 --
reboot is perfectly safe. I use it all the time. You just have to be the super-user to use it. It does the same thing as what the dashboard does.
The OP shoulda known all that, IMHO (like, you really want to give an ordinary user the ability to reboot or shutdown the system whenever s/he wants?).
-- sw
Rebooting via the dashboard is a wee-bit faster than calling reboot via the terminal, but that's really the only benefit.
I don't think we should bash (No pun intended) the OP for not knowing that reboot can't be done via a regular user under a normal setup since it's one of those things that he/she didn't know.
It means that a non-root user cannot reboot the system.
Really? To me, the message reads quite clear that the root user is logged on through SSH.
I’ve just tried it on an Ubuntu server as a non-root user, and get several “permission denied” errors - more in line with what I’d expect.
Rebooting via the dashboard is a wee-bit faster than calling reboot via the terminal.
Yes it is. Reboot in the terminal powers down the Linode from within the OS. For some reason, this causes the Linode to halt and you have to wait for the “Lassie” watchdog to see that it’s stopped, and restart it again. If you don’t have Lassie enabled, your Linode is dead in the water until you start it again in Manager.
A reboot through the Manager issues a shutdown signal to your Linode, waits for it to stop, then issues a boot-up event, so it’s much quicker.
I’ve never understood why this is - no other cloud/VPS provider I’ve used works this way.
@andysh Based on the screenshot it’s showing $ reboot not # reboot or sudo reboot which means the command is not being called by root.
Looks like the conversation went other way…
I'm not concerned about reboot at all.
My concern is, whether the output of reboot is indicating that my system has been compromised?
If not compromised, then what does User root is logged in on sshd. is telling to me?
@pratheekkarje see my first my reply which I explained why you were getting that error message.
Based on the screenshot it’s showing $ reboot not # reboot or sudo reboot which means the command is not being called by root.
Exactly what I did on my Linode, and I got a different error about not having enough permissions.
I’m not denying you need root privileges, and the command wasn’t being run with it, but the error message originally reported is clearly saying (at least, to me) there is a user logged on as root in sshd (i.e. SSH.)
To @pratheekkarje, what do you get if you run “who”?