It’s not really an OS problem: it’s the userland allocator that needs to implement this. So on Linux that would mostly be a glibc change to how malloc/free is i

It’s not really an OS problem: it’s the userland allocator that needs to implement this. So on Linux that would mostly be a glibc change to how malloc/free is implemented. The OS itself doesn’t know whether or not a processes memory page is logically „in use“. It only knows that once the process returns it (using for example munmap). But once you do that, any access crashes the process already.