[RESTRICT AUTOMERGE] Fix Integer Overflow in libpac
From the upstream patch
(https://chromium.googlesource.com/v8/v8.git/+/7b27040e66c8a83006aebc90fe97d21bb42156a7%5E%21/#F0):
"""
Harden JSFunction::CalculateInstanceSizeHelper(...)
"""
Bug: 117556220
Test: /data/local/nativetest/proxy_resolver_v8_unittest/proxy_resolver_v8_unittest
Test: gts-tradefed run gts --test \
com.google.android.gts.devicepolicy.DeviceOwnerTest#testProxyPacProxyTest \
--module GtsGmscoreHostTestCases
Test: PoC from bug report
Merged-In: I2e02d994f107e64e4f465b4d8a02d4159a95240e
Merged-In: I72321236f4d4cf8da993addc3ef7a1dc018c434b
Change-Id: I72321236f4d4cf8da993addc3ef7a1dc018c434b
diff --git a/src/objects.cc b/src/objects.cc
index e711a21..7a180ba 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -13103,6 +13103,46 @@
map->StartInobjectSlackTracking();
}
+namespace {
+bool FastInitializeDerivedMap(Isolate* isolate, Handle<JSFunction> new_target,
+ Handle<JSFunction> constructor,
+ Handle<Map> constructor_initial_map) {
+ // Create a new map with the size and number of in-object properties
+ // suggested by |function|.
+
+ // Link initial map and constructor function if the new.target is actually a
+ // subclass constructor.
+ if (!IsSubclassConstructor(new_target->shared()->kind())) {
+ return false;
+ }
+
+ Handle<Object> prototype(new_target->instance_prototype(), isolate);
+ InstanceType instance_type = constructor_initial_map->instance_type();
+ DCHECK(CanSubclassHaveInobjectProperties(instance_type));
+ int internal_fields =
+ JSObject::GetInternalFieldCount(*constructor_initial_map);
+ int pre_allocated = constructor_initial_map->GetInObjectProperties() -
+ constructor_initial_map->unused_property_fields();
+ int instance_size;
+ int in_object_properties;
+ new_target->CalculateInstanceSizeForDerivedClass(
+ instance_type, internal_fields, &instance_size,
+ &in_object_properties);
+
+ int unused_property_fields = in_object_properties - pre_allocated;
+ Handle<Map> map =
+ Map::CopyInitialMap(constructor_initial_map, instance_size,
+ in_object_properties, unused_property_fields);
+ map->set_new_target_is_base(false);
+
+ JSFunction::SetInitialMap(new_target, map, prototype);
+ map->SetConstructor(*constructor);
+ map->set_construction_counter(Map::kNoSlackTracking);
+ map->StartInobjectSlackTracking();
+ return true;
+}
+
+} // namespace
// static
MaybeHandle<Map> JSFunction::GetDerivedMap(Isolate* isolate,
@@ -13121,42 +13161,10 @@
// Check that |function|'s initial map still in sync with the |constructor|,
// otherwise we must create a new initial map for |function|.
- if (function->has_initial_map() &&
- function->initial_map()->GetConstructor() == *constructor) {
+ if (FastInitializeDerivedMap(isolate, function, constructor,
+ constructor_initial_map)) {
return handle(function->initial_map(), isolate);
}
-
- // Create a new map with the size and number of in-object properties
- // suggested by |function|.
-
- // Link initial map and constructor function if the new.target is actually a
- // subclass constructor.
- if (IsSubclassConstructor(function->shared()->kind())) {
- Handle<Object> prototype(function->instance_prototype(), isolate);
- InstanceType instance_type = constructor_initial_map->instance_type();
- DCHECK(CanSubclassHaveInobjectProperties(instance_type));
- int internal_fields =
- JSObject::GetInternalFieldCount(*constructor_initial_map);
- int pre_allocated = constructor_initial_map->GetInObjectProperties() -
- constructor_initial_map->unused_property_fields();
- int instance_size;
- int in_object_properties;
- function->CalculateInstanceSizeForDerivedClass(
- instance_type, internal_fields, &instance_size,
- &in_object_properties);
-
- int unused_property_fields = in_object_properties - pre_allocated;
- Handle<Map> map =
- Map::CopyInitialMap(constructor_initial_map, instance_size,
- in_object_properties, unused_property_fields);
- map->set_new_target_is_base(false);
-
- JSFunction::SetInitialMap(function, map, prototype);
- map->SetConstructor(*constructor);
- map->set_construction_counter(Map::kNoSlackTracking);
- map->StartInobjectSlackTracking();
- return map;
- }
}
// Slow path, new.target is either a proxy or can't cache the map.
@@ -13756,15 +13764,17 @@
int* instance_size,
int* in_object_properties) {
int header_size = JSObject::GetHeaderSize(instance_type);
- DCHECK_LE(requested_internal_fields,
- (JSObject::kMaxInstanceSize - header_size) >> kPointerSizeLog2);
+ int max_nof_fields =
+ (JSObject::kMaxInstanceSize - header_size) >> kPointerSizeLog2;
+ CHECK_LE(max_nof_fields, JSObject::kMaxInObjectProperties);
+ *in_object_properties = Min(requested_in_object_properties, max_nof_fields);
+ CHECK_LE(requested_internal_fields, max_nof_fields - *in_object_properties);
*instance_size =
- Min(header_size +
- ((requested_internal_fields + requested_in_object_properties)
- << kPointerSizeLog2),
- JSObject::kMaxInstanceSize);
- *in_object_properties = ((*instance_size - header_size) >> kPointerSizeLog2) -
- requested_internal_fields;
+ header_size +
+ ((requested_internal_fields + *in_object_properties) << kPointerSizeLog2);
+ CHECK_EQ(*in_object_properties,
+ ((*instance_size - header_size) >> kPointerSizeLog2) -
+ requested_internal_fields);
}
@@ -13789,7 +13799,13 @@
if (!current->IsJSFunction()) break;
JSFunction* func = JSFunction::cast(current);
SharedFunctionInfo* shared = func->shared();
- expected_nof_properties += shared->expected_nof_properties();
+ int count = shared->expected_nof_properties();
+ // Check that the estimate is sane.
+ if (expected_nof_properties <= JSObject::kMaxInObjectProperties - count) {
+ expected_nof_properties += count;
+ } else {
+ expected_nof_properties = JSObject::kMaxInObjectProperties;
+ }
if (!IsSubclassConstructor(shared->kind())) {
break;
}
diff --git a/src/objects.h b/src/objects.h
index 747a4f0..67c233f 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2649,6 +2649,9 @@
static const int kHeaderSize = kElementsOffset + kPointerSize;
STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
+ static const int kMaxInObjectProperties =
+ (kMaxInstanceSize - kHeaderSize) >> kPointerSizeLog2;
+ STATIC_ASSERT(kMaxInObjectProperties <= kMaxNumberOfDescriptors);
typedef FlexibleBodyDescriptor<JSReceiver::kPropertiesOffset> BodyDescriptor;
