linux - Can't reset permissions on amazon ec2

I've a big problem:

when I try to sudo something, this is what append:

sudo: /etc/sudo.conf is owned by uid 222, should be 0
sudo: /etc/sudoers is owned by uid 222, should be 0
sudo: no valid sudoers sources found, quitting
sudo: unable to initialize policy plugin

I tried to detach volume and retach it into a new istance, then I mount it and I set right permission also with chown and chmod: doesn't work.

I also tried this:

chown root:root /etc/sudoers
chmod 440 /etc/sudoers
chown -R root:root /etc/sudoers.d
chmod  755 /etc/sudoers.d

chmod  440 /etc/sudoers.d/*

same result: doesn't work.
Worse I can't connect to ssh.

How can I fix this ?

here debug with -vv:

debug1: /etc/ssh/ssh_config line 50: Applying options for *
debug2: ssh_connect: needpriv 0
ssh: Could not resolve hostname ec2-user: Name or service not known

Really thanks for support.