test.c

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

int main(){
        size_t *x = malloc(0x10);

        size_t *a = malloc(0x500);
        size_t* b = malloc(0x10);

        x[2] = -0x10;
        x[3] = 0x510;
        a[1] = -0x10;

        x[0] = &a[0];
        a[2] = &x[-3];
        a[3] = &x[-2];


        free(a);


}