TNS-12555 / TNS-12560 / TNS-00525 Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))

Few days back  got an issue when tried to start the listener

TNSLSNR for Linux: Version 10.2.0.2.0 – Production
System parameter file is /u01/app/oracle/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/oracle/product/10.2.0/db_1/network/log/listener.log
Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))
TNS-12555: TNS:permission denied
TNS-12560: TNS:protocol adapter error
TNS-00525: Insufficient privilege for operation
Linux Error: 1: Operation not permitted
  
Causes

1) Ensure that /tmp/.oracle or /var/tmp/.oracle directory exists.
 2) If the /tmp directory has reached full capacity, this would cause the listener to fail to write the socket files.

when i exprore found below directories exists/var/tmp/.oracle  but still got error
then  recreated /var/tmp/.oracle directory using below steps

cd /var/tmp/

ls -lrtha

cp .oracle .oracleback

mkdir .oracle

chmod 01777 .oracle

chown root  .oracle

chgrp root  .oracle

Start the listener and it started successfully J J