コンソールデバイスの所有権は root だけに制限しなさいというので。こういうこと？
cp -a /etc/security/console.perms.d/50-default.perms /etc/security/console.perms.d/50-default.perms.orig
sed -i 's/^[\s]*\(<console>\|<xconsole>\)/#\1/' /etc/security/console.perms.d/50-default.perms
cp -a /etc/security/console.perms /etc/security/console.perms.orig
sed -i \
-e 's/^\(<console>.*\)/#\1\n<console>=tty[0-9][0-9]* vc\/[0-9][0-9]* :0\\.[0-9] :0/' \
-e 's/^\(<xconsole>.*\)/#\1\n<xconsole>=:0\\.[0-9] :0/' \
/etc/security/console.perms
/sbin/pam_console_apply -r
