Is it secure to use malloc?

Question

Somebody told me that allocating with malloc is not secure anymore, I'm not a C/C++ guru but I've made some stuff with malloc and C/C++. Does anyone know about what risks I'm into?

Quoting him:

[..] But indeed the weak point of C/C++ it is the security, and the Achilles' heel is indeed malloc and the abuse of pointers. C/C++ it is a well known insecure language. [..] There would be few apps in what I would not recommend to continue programming with C++."

Answer 1

Maybe your friend is older, and isn't familiar with how things work now - I used to think C and C++ were effectively the same until I discovered many new things about the language that have come out in the last 10 years (most of my teachers were old-school Bell Laboratories guys who wrote primarily in C and had only a cursory knowledge of C++ - and Bell Laboratories engineers invented C++!). Don't laugh at him/her - you might be there someday too!

I think your friend is uncomfortable with the idea that you have to do your own memory management - ie, its easy to make mistakes. In that regard, it is insecure and he/she is correct... However, that insecure aspect can be overcome with good programming practices, like RAII and using smart pointers.

For many applications, though, having automated garbage collection is probably fine, and some programmers are confused about how pointers work, so as far as getting new, inexperienced developers to program effectively in C/C++ without some training might be difficult. Which is maybe why your friend thinks C/C++ should be avoided.

Answer 2

It's the only way to allocate and deallocate memory in C natively. If you misuse it, it can be as insecure as anything else. Microsoft provides some "secure" versions of other functions, that take an extra size_t parametre - maybe your friend was referring to something similar? If that's the case, perhaps he simply prefers calloc() over malloc()?

Answer 3

If you are using C, you have to use malloc to allocate memory, unless you have a third-party library that will allocate / manage your memory for you.

Certainly your friend has a point that it is difficult to write secure code in C, especially when you are allocating memory and dealing with buffers. But we all know that, right? :)