Created attachment 525570 [details]
strace of the script on 64bit

Description of problem:

On RHEL 6.1 64bit the following ksh never comes back:

#!/bin/ksh
f_cmd () {
	CMD="$1"
	OUT="$(eval "$CMD" 2>&1)"
	echo "$OUT"
}
f_cmd "dd if=/dev/zero bs=128001 count=1 | cat | cat >/dev/null"

Version-Release number of selected component (if applicable):

ksh-20100621-6.el6.x86_64

How reproducible:

always

Steps to Reproduce:
1. run the script from above on a 64bit RHEL 6.1 machine
  
Actual results:

The script never exits

Expected results:

Script should exit after executing the commands

Additional info:

The problem only occurs on 64bit architecture, not on 32bit. Also, current fedora 64bit does not show the problem.