Index: clang/lib/Analysis/FlowSensitive/RecordOps.cpp
===================================================================
--- clang/lib/Analysis/FlowSensitive/RecordOps.cpp
+++ clang/lib/Analysis/FlowSensitive/RecordOps.cpp
@@ -17,29 +17,37 @@
 void clang::dataflow::copyRecord(AggregateStorageLocation &Src,
                                  AggregateStorageLocation &Dst,
                                  Environment &Env) {
+  auto SrcType = Src.getType().getCanonicalType().getUnqualifiedType();
+  auto DstType = Dst.getType().getCanonicalType().getUnqualifiedType();
+
+  auto SrcDecl = SrcType->getAsCXXRecordDecl();
+  auto DstDecl = DstType->getAsCXXRecordDecl();
+
+  bool compatibleTypes =
+      SrcType == DstType ||
+      (SrcDecl && DstDecl && SrcDecl->isDerivedFrom(DstDecl));
+
   LLVM_DEBUG({
-    if (Dst.getType().getCanonicalType().getUnqualifiedType() !=
-        Src.getType().getCanonicalType().getUnqualifiedType()) {
+    if (!compatibleTypes) {
       llvm::dbgs() << "Source type " << Src.getType() << "\n";
       llvm::dbgs() << "Destination type " << Dst.getType() << "\n";
     }
   });
-  assert(Dst.getType().getCanonicalType().getUnqualifiedType() ==
-         Src.getType().getCanonicalType().getUnqualifiedType());
+  assert(compatibleTypes);
 
-  for (auto [Field, SrcFieldLoc] : Src.children()) {
-    assert(SrcFieldLoc != nullptr);
+  for (auto [Field, DstFieldLoc] : Dst.children()) {
+    assert(DstFieldLoc != nullptr);
 
-    StorageLocation &DstFieldLoc = Dst.getChild(*Field);
+    StorageLocation &SrcFieldLoc = Src.getChild(*Field);
 
     if (Field->getType()->isRecordType()) {
-      copyRecord(cast<AggregateStorageLocation>(*SrcFieldLoc),
-                 cast<AggregateStorageLocation>(DstFieldLoc), Env);
+      copyRecord(cast<AggregateStorageLocation>(SrcFieldLoc),
+                 cast<AggregateStorageLocation>(*DstFieldLoc), Env);
     } else {
-      if (Value *Val = Env.getValue(*SrcFieldLoc))
-        Env.setValue(DstFieldLoc, *Val);
+      if (Value *Val = Env.getValue(SrcFieldLoc))
+        Env.setValue(*DstFieldLoc, *Val);
       else
-        Env.clearValue(DstFieldLoc);
+        Env.clearValue(*DstFieldLoc);
     }
   }
 
Index: clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
===================================================================
--- clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -2290,6 +2290,28 @@
          ASTContext &ASTCtx) {});
 }
 
+TEST(TransferTest, CopyConstructorWithUncheckedDerivedToBaseImplicitCast) {
+  std::string Code = R"(
+  class A {
+  public:
+      A(const A&) = default;
+      int a;
+  };
+
+  class target : public A {
+  public:
+      target(const target& b) = default;
+      target* copy() {
+          return new target(*this);
+      }
+  };
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {});
+}
+
 TEST(TransferTest, MoveConstructor) {
   std::string Code = R"(
     namespace std {