TNS-12518: TNS:listener could not hand off client connection

 TNS-12518: TNS:listener could not hand off client connection

While Connecting to oracle RAC database using sqlplus gives the following errors:

TNS-12518: TNS:listener could not hand off client connection
TNS-12547: TNS:lost contact
 TNS-12560: TNS:protocol adapter error
  TNS-00517: Lost contact
   Linux Error: 32: Broken pipe

Solution:

Check the permissions on the oracle executable in the RDBMS Home

cd $ORACLE_HOME/bin

ls -ltr oracle

It should have 6751 permission

chmod 6751 oracle