bin/55346: /bin/sh eats memory and CPU infinitely

[Eugene Grosbein]

Hi!

It seems /bin/sh in 4.8-STABLE has problem with SIGCHLD processing.
In short, it often fails to process it correctly, zombies float
around, jobs are not marked as finished in jobtab[] that fills memory
and takes much CPU to be processed.

Run this one-liner using /bin/sh and see hundreds of zombies:

#!/bin/sh
while :; do : & done

A kernel will halt this as soon as it reaches limits and write a message:

/kernel: maxproc limit exceeded by uid 0, please see tuning(7) and login.conf(5).

Eugene Grosbein