What is the simplest standard conform way to produce a Segfault in C?

Question

I think the question says it all. An example covering most standards from C89 to C11 would be helpful. I though of this one, but I guess it is just undefined behaviour:

Answer 1

If we assume we are not raising a signal calling raise, segmentation fault is likely to come from undefined behavior. Undefined behavior is undefined and a compiler is free to refuse to translate so no answer with undefined is guaranteed to fail on all implementations. Moreover a program which invokes undefined behavior is an erroneous program.

But this one is the shortest I can get that segfault on my system:

main(){main();}

(I compile with gcc and -std=c89 -O0).

And by the way, does this program really invokes undefined bevahior?