Why doesn't the OS crash if I dereference a null pointer?

Question

Dereferencing a null pointer results in undefined behavior. In practice it usually means that my program will crash. But why doesn\'t the OS crash? Because if my progra

Answer 1

Memory access is protected in every major OS. You cannot simply write a program that manipulates memory that was not allocated for it (assuming a pointer is not initialized for example, it could be ANY address). So, every time a program tries to access some address space that does not belong to it, the OS will send a signal to terminate the program (resulting in the ultimate famous "Segmentation fault", familiar to any C/C++ programmer).