If you put a symlink from /dev in /etc/securetty, like # cd /dev # ln -s ttyS0 ttyFOO # grep -v ttyS0 /etc/securetty > /tmp/securetty # echo ttyFOO >> /tmp/securetty # mv /tmp/securetty /etc root can't log in on /dev/ttyS0 even though ttyFOO is in /etc/securetty
This can be viewed as a feature - you are not logging in from ttyF00 but from ttyS0, so ttyS0 should be in securetty not ttyF00.