And there's https://en.wikipedia.org/wiki/Zombie_process too

Not the same thing by any means - they don't indicate something is wrong with kernel or hardware.

The zombie process state is a normal transient state for all exiting processes where the only remaining function of the process is as a container for the exiting process's id and exit status; they go away once the parent process calls some flavor of the "wait" system call to collect the exit status. A pileup of zombies indicates a userspace bug: a negligent parent process that isn't collecting the exit status in a timely manner.