Java (OpenJDK 9), 311 bytes
import sun.misc.Unsafe;import java.lang.reflect.Constructor;class Main{public static void main(String[] args) throws Exception{Constructor<Unsafe> unsafeConstructor=Unsafe.class.getDeclaredConstructor();unsafeConstructor.setAccessible(true);Unsafe unsafe=unsafeConstructor.newInstance();unsafe.getAddress(0);}}
Ungolfed:
import sun.misc.Unsafe;
import java.lang.reflect.Constructor;
public class SegFault {
public static void main(String[] args) throws Exception {
Constructor<Unsafe> unsafeConstructor = Unsafe.class.getDeclaredConstructor();
unsafeConstructor.setAccessible(true);
Unsafe unsafe = unsafeConstructor.newInstance();
System.out.println(unsafe.getAddress(0));
}
}