Possibly (dunno). But they refer to that on slide 7:
- We also introduced new safer APIs like reallocarray()
- I wrote a big diff for nginx to adopt reallocarray() other such techniques
- And it got rejected.
It's OpenBSD specific. But it's also just 10 lines of portable C that are permissively licensed and can be added to any project without problems. It's even in a separate source file for this very purpose [1]