diff --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -639,7 +639,7 @@
           if (ClassId) {
             resizeTaggedChunk(reinterpret_cast<uptr>(OldTaggedPtr) + OldSize,
                               reinterpret_cast<uptr>(OldTaggedPtr) + NewSize,
-                              NewSize, BlockEnd);
+                              NewSize, untagPointer(BlockEnd));
             storePrimaryAllocationStackMaybe(Options, OldPtr);
           } else {
             storeSecondaryAllocationStackMaybe(Options, OldPtr, NewSize);
@@ -1153,9 +1153,10 @@
   // memory tag space, which getInlineErrorInfo() normally relies on to match
   // address tags against chunks. To allow matching in this case we store the
   // address tag in the first byte of the chunk.
-  void storeEndMarker(uptr End, uptr Size, uptr BlockEnd) {
+  void storeEndMarker(uptr End, uptr Size, uptr UntaggedBlockEnd) {
+    DCHECK_EQ(UntaggedBlockEnd, untagPointer(UntaggedBlockEnd));
     uptr UntaggedEnd = untagPointer(End);
-    if (UntaggedEnd != BlockEnd) {
+    if (UntaggedEnd != UntaggedBlockEnd) {
       storeTag(UntaggedEnd);
       if (Size == 0)
         *reinterpret_cast<u8 *>(UntaggedEnd) = extractTag(End);