In case someone finds it as interesting as me - old but gold writeup about stack smashing with detailed mitigations explanations:

http://phrack.org/issues/67/13.html

Learned a ton about internal stuff from it (as usual with Phrack though).

The article provides a great overview of all the available features to protect the stack.

I have previously written a detailed article on the -fstack-protector part, maybe it is helpful to someone: https://www.productive-cpp.com/hardening-cpp-programs-stack-protector/