ORA-00205: error in identifying control file during DB upgrade from 11.2.0.3 to 11.2.0.4

scenario : we were doing a upgrade from 11.2.0.3 to 11.2.0.4.
we have newly installed 11.2.0.4 software and going to upgrade the first DB
we ran into the below issue while "startup upgrade" command as per MOS note 1054033.1 we found out the issue lies with the wrong group ownership of oracle executable as shown below
after making below changes on all RAC nodes my upgrade went fine without any issue

In my case, the oracle binary is owned by
-rwsr-s--x 1 oracle oinstall
instead of
-rwsr-s--x 1 oracle asmadmin

solution:

1. Manually change the oracle binary ownership and permission:

as root user:
# cd $ORACLE_HOME/bin
# chgrp asmadmin oracle
# chmod 6751 oracle
# ls -l oracle

--below is the error snapshot
subhen_host:ORCL > sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Wed May 11 15:29:14 2016

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup upgrade
ORACLE instance started.

Total System Global Area 1570009088 bytes
Fixed Size                  2253584 bytes
Variable Size             469765360 bytes
Database Buffers         1073741824 bytes
Redo Buffers               24248320 bytes
ORA-00205: error in identifying control file, check alert log for more info