Fixed
Created: Mar 30, 2017
Updated: Dec 3, 2018
Resolved Date: Apr 12, 2017
Found In Version: 8.0
Fix Version: 8.0.0.17
Severity: Standard
Applicable for: Wind River Linux 8
Component/s: Kernel
A process can create permanent zombie children by cloning a thread, calling ptrace() on it, then exiting. If the init system is not waiting for exiting processes in the right way, that particular thread will go unnoticed and unreaped.
root@qemu3:~# ./zombie
root@qemu3:~#
root@qemu3:~# ps aux | grep -i zombie
root 361 0.0 0.0 0 0 ttyS0 Zl 07:25 0:00 [zombie] <defunct>
root 365 0.0 0.0 4420 768 ttyS0 S+ 07:25 0:00 grep -i zombie
root@qemu3:~#
root@qemu3:~# kill -9 361 362
root@qemu3:~#
root@qemu3:~# ps aux | grep -i zombie
root 361 0.0 0.0 0 0 ttyS0 Zl 07:25 0:00 [zombie] <defunct>
root 377 0.0 0.0 4420 788 ttyS0 S+ 07:45 0:00 grep -i zombie
Run the attached reproducer.
root@qemu3:~# ./zombie
root@qemu3:~#
root@qemu3:~# ps aux | grep -i zombie
root 361 0.0 0.0 0 0 ttyS0 Zl 07:25 0:00 [zombie] <defunct>
root 365 0.0 0.0 4420 768 ttyS0 S+ 07:25 0:00 grep -i zombie
root@qemu3:~#
root@qemu3:~# kill -9 361 362
root@qemu3:~#
root@qemu3:~# ps aux | grep -i zombie
root 361 0.0 0.0 0 0 ttyS0 Zl 07:25 0:00 [zombie] <defunct>
root 377 0.0 0.0 4420 788 ttyS0 S+ 07:45 0:00 grep -i zombie
