This is xnu-8019. See this file in:
OPTIONS/CONFIG_UBSAN_MINIMAL   optional config_ubsan_minimal

san/memory/kasan-arm64.c       optional config_kasan
san/memory/kasan-test-arm64.s  optional config_kasan

san/memory/kasan-classic.c     optional config_kasan

san/memory/ubsan_minimal.c     optional config_ubsan_minimal