diff --git a/mlir/lib/Dialect/Linalg/Transforms/ComprehensiveBufferize.cpp b/mlir/lib/Dialect/Linalg/Transforms/ComprehensiveBufferize.cpp
--- a/mlir/lib/Dialect/Linalg/Transforms/ComprehensiveBufferize.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/ComprehensiveBufferize.cpp
@@ -795,9 +795,8 @@
     Value v;
   };
 
-  using EquivalenceClassRangeType =
-      llvm::iterator_range<
-          llvm::EquivalenceClasses<ValueWrapper>::member_iterator>;
+  using EquivalenceClassRangeType = llvm::iterator_range<
+      llvm::EquivalenceClasses<ValueWrapper>::member_iterator>;
   /// Check that aliasInfo for `v` exists and return a reference to it.
   EquivalenceClassRangeType getAliases(Value v) const;
 
@@ -1106,15 +1105,13 @@
 
 void BufferizationAliasInfo::printAliases(raw_ostream &os) const {
   os << "\n/===================== AliasInfo =====================\n";
-  for (auto it = aliasInfo.begin(), eit = aliasInfo.end(); it != eit;
-       ++it) {
+  for (auto it = aliasInfo.begin(), eit = aliasInfo.end(); it != eit; ++it) {
     if (!it->isLeader())
       continue;
     Value leader = it->getData();
     os << "|\n| -- leader: " << printValueInfo(leader, /*prefix=*/false)
        << '\n';
-    for (auto mit = aliasInfo.member_begin(it),
-              meit = aliasInfo.member_end();
+    for (auto mit = aliasInfo.member_begin(it), meit = aliasInfo.member_end();
          mit != meit; ++mit) {
       Value v = static_cast<Value>(*mit);
       os << "| ---- equivalent member: " << printValueInfo(v, /*prefix=*/false)
@@ -1148,13 +1145,12 @@
 BufferizationAliasInfo::getAliases(Value v) const {
   DenseSet<Value> res;
   auto it = aliasInfo.findValue(aliasInfo.getLeaderValue(v));
-    for (auto mit = aliasInfo.member_begin(it),
-              meit = aliasInfo.member_end();
-         mit != meit; ++mit) {
-      res.insert(static_cast<Value>(*mit));
-    }
+  for (auto mit = aliasInfo.member_begin(it), meit = aliasInfo.member_end();
+       mit != meit; ++mit) {
+    res.insert(static_cast<Value>(*mit));
+  }
   return BufferizationAliasInfo::EquivalenceClassRangeType(
-          aliasInfo.member_begin(it), aliasInfo.member_end());
+      aliasInfo.member_begin(it), aliasInfo.member_end());
 }
 
 /// This is one particular type of relationship between ops on tensors that
@@ -2631,6 +2627,11 @@
 
   // 2. Rewrite the terminator without the inPlace bufferizable values.
   ValueRange retValues{returnValues};
+  if (llvm::any_of(retValues.getTypes(), [](Type t) {
+        return t.isa<MemRefType, UnrankedMemRefType>();
+      }))
+    return returnOp->emitError("memref return type is unsupported");
+
   FunctionType bufferizedFuncType = getOrCreateBufferizedFunctionType(
       funcOp, funcOp.getType().getInputs(), retValues.getTypes(),
       bufferizedFunctionTypes);
diff --git a/mlir/test/Dialect/Linalg/comprehensive-module-bufferize-invalid.mlir b/mlir/test/Dialect/Linalg/comprehensive-module-bufferize-invalid.mlir
--- a/mlir/test/Dialect/Linalg/comprehensive-module-bufferize-invalid.mlir
+++ b/mlir/test/Dialect/Linalg/comprehensive-module-bufferize-invalid.mlir
@@ -130,3 +130,13 @@
   %r = "marklar"(%A) : (tensor<4xf32>) -> (tensor<4xf32>)
   return %r: tensor<4xf32>
 }
+
+// -----
+
+func @mini_test_case1() -> tensor<10x20xf32> {
+  %f0 = constant 0.0 : f32
+  %t = linalg.init_tensor [10, 20] : tensor<10x20xf32>
+  %r = linalg.fill(%f0, %t) : f32, tensor<10x20xf32> -> tensor<10x20xf32>
+  // expected-error @+1 {{memref return type is unsupported}}
+  return %r : tensor<10x20xf32>
+}