Claudio André authored Aug 14, 2017 and Philip Chimento committed Aug 24, 2017

AddressSanitizer (or ASan) is a programming tool that detects memory
corruption bugs such as buffer overflows or use after free. AddressSanitizer
is based on compiler instrumentation.

UndefinedBehaviorSanitizer (or UBSan) is a fast undefined behavior
detector. It modifies the program at compile-time to catch errors
such as using misaligned or null pointer and signed integer overflow.

The llvm.org states that Sanitizers have found thousands of bugs everywhere.
Sanitizers running during CI can prevent bugs from taking up residence. They
are helper tools to maintain bugs out.

https://bugzilla.gnome.org/show_bug.cgi?id=783220