Troubleshooting: Cannot log in as root with su command
I was seeing something strange behavior on one of my server.I can log in as 'root' user using ssh but when I try to login as 'root' user using su - , it fails with " incorrect password" error.
$ su - Password: su: incorrect password
After some poking on the system , I was able to identify the issue . The issue was missing SUID permission for su command.
Setting SUID command for su command resolved the issue .
# ls -l /bin/su -rwxr-xr-x. 1 root root 34904 Oct 5 2011 /bin/su # chmod u+s /bin/su# ls -l /bin/su -rwsr-xr-x. 1 root root 34904 Oct 5 2011 /bin/su # su - user $ su - Password: # id uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel)