[Backport] CVE-2023-3079: Type Confusion in V8

Cherry-pick of patch originally reviewed on
https://chromium-review.googlesource.com/c/v8/v8/+/4590637:
Fix store handler selection for arguments objects

M108 merge issues:
    src/diagnostics/objects-printer.cc:
      Type conflicts for the handler variable on and
      the IsWeakFixedArray() check isn't present in 108; kept
      the code changes from the fix.

Drive-by: fix printing of handlers in --trace-feedback-updates mode.

(cherry picked from commit e144f3b71e64e01d6ffd247eb15ca1ff56f6287b)

Bug: chromium:1450481
Change-Id: I1c0084701f7f8959da508481cab7a81a2bca3c8d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4584248
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#88021}
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4590637
Commit-Queue: Roger Felipe Zanoni da Silva <rzanoni@google.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/branch-heads/10.8@{#66}
Cr-Branched-From: f1bc03fd6b4c201abd9f0fd9d51fb989150f97b9-refs/heads/10.8.168@{#1}
Cr-Branched-From: 237de893e1c0a0628a57d0f5797483d3add7f005-refs/heads/main@{#83672}
Reviewed-on: https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/486078
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

chromium/v8/src/diagnostics/objects-printer.cc

@@ -1308,8 +1308,18 @@ void FeedbackNexus::Print(std::ostream& os) {
     case FeedbackSlotKind::kSetKeyedStrict: {
       os << InlineCacheState2String(ic_state());
       if (ic_state() == InlineCacheState::MONOMORPHIC) {
-        os << "\n   " << Brief(GetFeedback()) << ": ";
-        StoreHandler::PrintHandler(GetFeedbackExtra().GetHeapObjectOrSmi(), os);
+        HeapObject feedback = GetFeedback().GetHeapObject();
+        HeapObject feedback_extra = GetFeedbackExtra().GetHeapObject();
+        if (feedback.IsName()) {
+          os << " with name " << Brief(feedback);
+          WeakFixedArray array = WeakFixedArray::cast(feedback_extra);
+          os << "\n   " << Brief(array.Get(0)) << ": ";
+          Object handler = array.Get(1).GetHeapObjectOrSmi();
+          StoreHandler::PrintHandler(handler, os);
+        } else {
+          os << "\n   " << Brief(feedback) << ": ";
+          StoreHandler::PrintHandler(feedback_extra, os);
+        }
       } else if (ic_state() == InlineCacheState::POLYMORPHIC) {
         WeakFixedArray array =
             WeakFixedArray::cast(GetFeedback().GetHeapObject());

chromium/v8/src/ic/handler-configuration.cc

@@ -584,8 +584,11 @@ void StoreHandler::PrintHandler(Object handler, std::ostream& os) {
     os << ", validity cell = ";
     store_handler.validity_cell().ShortPrint(os);
     os << ")" << std::endl;
+  } else if (handler.IsMap()) {
+    os << "StoreHandler(field transition to " << Brief(handler) << ")"
+       << std::endl;
   } else {
-    os << "StoreHandler(<unexpected>)(" << Brief(handler) << ")";
+    os << "StoreHandler(<unexpected>)(" << Brief(handler) << ")" << std::endl;
   }
 }
 

chromium/v8/src/ic/ic.cc

@@ -2296,10 +2296,18 @@ Handle<Object> KeyedStoreIC::StoreElementHandler(
              receiver_map->has_sealed_elements() ||
              receiver_map->has_nonextensible_elements() ||
              receiver_map->has_typed_array_or_rab_gsab_typed_array_elements()) {
+    // TODO(jgruber): Update counter name.
     TRACE_HANDLER_STATS(isolate(), KeyedStoreIC_StoreFastElementStub);
-    code = StoreHandler::StoreFastElementBuiltin(isolate(), store_mode);
-    if (receiver_map->has_typed_array_or_rab_gsab_typed_array_elements()) {
-      return code;
+    if (receiver_map->IsJSArgumentsObjectMap() &&
+        receiver_map->has_fast_packed_elements()) {
+      // Allow fast behaviour for in-bounds stores while making it miss and
+      // properly handle the out of bounds store case.
+      code = StoreHandler::StoreFastElementBuiltin(isolate(), STANDARD_STORE);
+    } else {
+      code = StoreHandler::StoreFastElementBuiltin(isolate(), store_mode);
+      if (receiver_map->has_typed_array_or_rab_gsab_typed_array_elements()) {
+        return code;
+      }
     }
   } else if (IsStoreInArrayLiteralIC()) {
     // TODO(jgruber): Update counter name.
@@ -2310,7 +2318,7 @@ Handle<Object> KeyedStoreIC::StoreElementHandler(
     TRACE_HANDLER_STATS(isolate(), KeyedStoreIC_StoreElementStub);
     DCHECK(DICTIONARY_ELEMENTS == receiver_map->elements_kind() ||
            receiver_map->has_frozen_elements());
-    code = StoreHandler::StoreSlow(isolate(), store_mode);
+    return StoreHandler::StoreSlow(isolate(), store_mode);
   }
 
   if (IsAnyDefineOwn() || IsStoreInArrayLiteralIC()) return code;

chromium/v8/src/objects/map-inl.h

@@ -589,6 +589,10 @@ bool Map::has_fast_elements() const {
   return IsFastElementsKind(elements_kind());
 }
 
+bool Map::has_fast_packed_elements() const {
+  return IsFastPackedElementsKind(elements_kind());
+}
+
 bool Map::has_sloppy_arguments_elements() const {
   return IsSloppyArgumentsElementsKind(elements_kind());
 }

chromium/v8/src/objects/map.h

@@ -422,6 +422,7 @@ class Map : public TorqueGeneratedMap<Map, HeapObject> {
   inline bool has_fast_smi_or_object_elements() const;
   inline bool has_fast_double_elements() const;
   inline bool has_fast_elements() const;
+  inline bool has_fast_packed_elements() const;
   inline bool has_sloppy_arguments_elements() const;
   inline bool has_fast_sloppy_arguments_elements() const;
   inline bool has_fast_string_wrapper_elements() const;