#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

int main() {
  uintptr_t* p1 = malloc(0x10);
  uintptr_t* p2 = malloc(0x10);
  free(p1);
  // XXX
  *p1 = (uintptr_t)p2 - 0x10;
  uintptr_t* p3 = malloc(0x100);
  free(p3);
  uintptr_t* p4 = malloc(0x1000);

  fprintf(stderr, "Overlap p2 & p4:%p, %p\n", p2, p4);
}