Index: llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -302,6 +302,12 @@
       IRB.CreateLoad(IRB.CreateIntToPtr(ShadowLong, IRB.getInt8PtrTy()));
   Value *TagMismatch = IRB.CreateICmpNE(PtrTag, MemTag);
 
+  if (ClEnableKhwasan) {
+    Value *TagNotIgnored = IRB.CreateICmpNE(PtrTag,
+        ConstantInt::get(PtrTag->getType(), 0xFF));
+    TagMismatch = IRB.CreateAnd(TagMismatch, TagNotIgnored);
+  }
+
   TerminatorInst *CheckTerm =
       SplitBlockAndInsertIfThen(TagMismatch, InsertBefore, !Recover,
                                 MDBuilder(*C).createBranchWeights(1, 100000));
Index: llvm/test/Instrumentation/HWAddressSanitizer/kernel.ll
===================================================================
--- llvm/test/Instrumentation/HWAddressSanitizer/kernel.ll
+++ llvm/test/Instrumentation/HWAddressSanitizer/kernel.ll
@@ -24,7 +24,9 @@
 
 ; CHECK: %[[MEMTAG:[^ ]*]] = load i8, i8* %[[E]]
 ; CHECK: %[[F:[^ ]*]] = icmp ne i8 %[[PTRTAG]], %[[MEMTAG]]
-; CHECK: br i1 %[[F]], label {{.*}}, label {{.*}}, !prof {{.*}}
+; CHECK: %[[G:[^ ]*]] = icmp ne i8 %[[PTRTAG]], -1
+; CHECK: %[[H:[^ ]*]] = and i1 %[[F]], %[[G]]
+; CHECK: br i1 %[[H]], label {{.*}}, label {{.*}}, !prof {{.*}}
 
 ; ABORT: call void asm sideeffect "brk #2304", "{x0}"(i64 %[[A]])
 ; ABORT: unreachable