I'm trying to figure out if the following is UB: https://godbolt.org/z/4xoK9hWr4

My curiosity stems from reading about the "debian openssl fiasco", which if I understand it correctly, started because of a similar pattern.

So far I've found this statement

If the lvalue designates an object of automatic storage duration that could have been declared with the register storage class (never had its address taken), and that object is uninitialized (not declared with an initializer and no assignment to it has been performed prior to use), the behavior is undefined.

6.3.2.1p2

which seems to not be it because in this case it could not be register class because we are taking a pointer to it. Annex J says this, but my understanding is it's not normative

The value of an object with automatic storage duration is used while it is indeterminate (6.2.4, 6.7.8, 6.8).

Thanks in advance.