Index: lib/Driver/SanitizerArgs.cpp
===================================================================
--- lib/Driver/SanitizerArgs.cpp
+++ lib/Driver/SanitizerArgs.cpp
@@ -100,6 +100,8 @@
     BlacklistFile = "dfsan_abilist.txt";
   else if (Kinds & CFI)
     BlacklistFile = "cfi_blacklist.txt";
+  else if (Kinds & Undefined)
+    BlacklistFile = "ubsan_blacklist.txt";
 
   if (BlacklistFile) {
     clang::SmallString<64> Path(D.ResourceDir);