Here is a script I created to kill ALL zombie processes. It uses the GDB debugger to attach to the parent process and send a waitpid to kill the zombie process. This will leave the parent live and only slay the zombie.
GDB debugger will need to be installed and you will need to be logged in with permissions to attach to a process. This has been tested on Centos 6.3
#!/bin/bash
##################################################################
# Script: Zombie Slayer
# Author: Mitch Milner
# Date: 03/13/2013 ---> A good day to slay zombies
#
# Requirements: yum install gdb
# permissions to attach to the parent process
#
# This script works by using a debugger to
# attach to the parent process and then issuing
# a waitpid to the dead zombie. This will not kill
# the living parent process.
##################################################################
clear
# Wait for user input to proceed, give user a chance to cancel script
echo "***********************************************************"
echo -e "This script will terminate all zombie process."
echo -e "Press [ENTER] to continue or [CTRL] + C to cancel:"
echo "***********************************************************"
read cmd_string
echo -e "\n"
# initialize variables
intcount=0
lastparentid=0
# remove old gdb command file
rm -f /tmp/zombie_slayer.txt
# create the gdb command file
echo "***********************************************************"
echo "Creating command file..."
echo "***********************************************************"
ps -e -o ppid,pid,stat,command | grep Z | sort | while read LINE; do
intcount=$((intcount+1))
parentid=`echo $LINE | awk '{print $1}'`
zombieid=`echo $LINE | awk '{print $2}'`
verifyzombie=`echo $LINE | awk '{print $3}'`
# make sure this is a zombie file and we are not getting a Z from
# the command field of the ps -e -o ppid,pid,stat,command
if [ "$verifyzombie" == "Z" ]
then
if [ "$parentid" != "$lastparentid" ]
then
if [ "$lastparentid" != "0" ]
then
echo "detach" >> /tmp/zombie_slayer.txt
fi
echo "attach $parentid" >> /tmp/zombie_slayer.txt
fi
echo "call waitpid ($zombieid,0,0)" >> /tmp/zombie_slayer.txt
echo "Logging: Parent: $parentid Zombie: $zombieid"
lastparentid=$parentid
fi
done
if [ "$lastparentid" != "0" ]
then
echo "detach" >> /tmp/zombie_slayer.txt
fi
# Slay the zombies with gdb and the created command file
echo -e "\n\n"
echo "***********************************************************"
echo "Slaying zombie processes..."
echo "***********************************************************"
gdb -batch -x /tmp/zombie_slayer.txt
echo -e "\n\n"
echo "***********************************************************"
echo "Script complete."
echo "***********************************************************"
Enjoy.