WebKit: use-after-free in WebCore::PositionIterator::decrement(CVE-2017-13797)

There is a use-after-free security vulnerability in WebKit. The vulnerability was confirmed on ASan build of WebKit nightly. ### ASan log: ``` ================================================================= ==29700==ERROR: AddressSanitizer: heap-use-after-free on address 0x607000149b24 at pc 0x00010fbb202a bp 0x7fff5f325d30 sp 0x7fff5f325d28 READ of size 4 at 0x607000149b24 thread T0 ==29700==WARNING: invalid path to external symbolizer! ==29700==WARNING: Failed to use and restart external symbolizer! #0 0x10fbb2029 in WebCore::Node::getFlag(WebCore::Node::NodeFlags) const (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xa029) #1 0x10fbbca5d in WebCore::Node::firstChild() const (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x14a5d) #2 0x10fcc7f58 in WebCore::Node::hasChildNodes() const (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x11ff58) #3 0x112068f8d in WebCore::PositionIterator::decrement() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x24c0f8d) #4 0x110492193 in WebCore::previousCandidate(WebCore::Position const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x8ea193) #5 0x112c860e4 in WebCore::VisiblePosition::canonicalPosition(WebCore::Position const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x30de0e4) #6 0x112c85dc7 in WebCore::VisiblePosition::init(WebCore::Position const&, WebCore::EAffinity) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x30dddc7) #7 0x112c8cfde in WebCore::VisibleSelection::setBaseAndExtentToDeepEquivalents() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x30e4fde) #8 0x112c8b43f in WebCore::VisibleSelection::validate(WebCore::TextGranularity) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x30e343f) #9 0x112c8b986 in WebCore::VisibleSelection::selectionFromContentsOfNode(WebCore::Node*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x30e3986) #10 0x11071c1f2 in WebCore::FrameSelection::selectAll() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xb741f2) #11 0x1104de2b0 in WebCore::executeSelectAll(WebCore::Frame&, WebCore::Event*, WebCore::EditorCommandSource, WTF::String const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x9362b0) #12 0x1104d8ab3 in WebCore::Editor::Command::execute(WTF::String const&, WebCore::Event*) const (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x930ab3) #13 0x11035900a in WebCore::Document::execCommand(WTF::String const&, bool, WTF::String const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x7b100a) #14 0x110f4e593 in WebCore::jsDocumentPrototypeFunctionExecCommandBody(JSC::ExecState*, WebCore::JSDocument*, JSC::ThrowScope&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x13a6593) #15 0x110f36068 in long long WebCore::IDLOperation<WebCore::JSDocument>::call<&(WebCore::jsDocumentPrototypeFunctionExecCommandBody(JSC::ExecState*, WebCore::JSDocument*, JSC::ThrowScope&)), (WebCore::CastedThisErrorBehavior)0>(JSC::ExecState&, char const*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x138e068) #16 0x43f9a9401027 (<unknown module>) #17 0x1084ace49 in llint_entry (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x16aae49) #18 0x1084ace49 in llint_entry (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x16aae49) #19 0x1084a5f6f in vmEntryToJavaScript (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x16a3f6f) #20 0x108109847 in JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1307847) #21 0x10808a88a in JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x128888a) #22 0x1076a3731 in JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x8a1731) #23 0x1076a39a2 in JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x8a19a2) #24 0x1076a3d13 in JSC::profiledCall(JSC::ExecState*, JSC::ProfilingReason, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x8a1d13) #25 0x110de6615 in WebCore::JSMainThreadExecState::profiledCall(JSC::ExecState*, JSC::ProfilingReason, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x123e615) #26 0x1111f96cd in WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&, WebCore::Event&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x16516cd) #27 0x110565010 in WebCore::EventTarget::fireEventListeners(WebCore::Event&, WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener>, 1ul, WTF::CrashOnOverflow, 16ul>) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x9bd010) #28 0x110564ae0 in WebCore::EventTarget::fireEventListeners(WebCore::Event&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x9bcae0) #29 0x110442051 in WebCore::DOMWindow::dispatchEvent(WebCore::Event&, WebCore::EventTarget*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x89a051) #30 0x110451c0f in WebCore::DOMWindow::dispatchLoadEvent() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x8a9c0f) #31 0x110344b0f in WebCore::Document::dispatchWindowLoadEvent() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x79cb0f) #32 0x11033ebad in WebCore::Document::implicitClose() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x796bad) #33 0x1106f13ed in WebCore::FrameLoader::checkCompleted() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xb493ed) #34 0x1106ee75c in WebCore::FrameLoader::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xb4675c) #35 0x11035e523 in WebCore::Document::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x7b6523) #36 0x1108e25d0 in WebCore::HTMLDocumentParser::prepareToStopParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xd3a5d0) #37 0x1103ff693 in WebCore::DocumentWriter::end() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x857693) #38 0x1103c0736 in WebCore::DocumentLoader::finishedLoading() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x818736) #39 0x10fe3c047 in WebCore::CachedResource::checkNotify() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x294047) #40 0x10fe34df1 in WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x28cdf1) #41 0x11290c661 in WebCore::SubresourceLoader::didFinishLoading(WebCore::NetworkLoadMetrics const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x2d64661) #42 0x10140243b in WebKit::WebResourceLoader::didFinishResourceLoad(WebCore::NetworkLoadMetrics const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xb1343b) #43 0x1014056d9 in void IPC::handleMessage<Messages::WebResourceLoader::DidFinishResourceLoad, WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)>(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xb166d9) #44 0x101404bc9 in WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xb15bc9) #45 0x100bf6117 in WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0x307117) #46 0x1009d5695 in IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xe6695) #47 0x1009dea48 in IPC::Connection::dispatchOneMessage() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xefa48) #48 0x108b248e3 in WTF::RunLoop::performWork() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1d228e3) #49 0x108b251b1 in WTF::RunLoop::performWork(void*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1d231b1) #50 0x7fffd52af320 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation:x86_64h+0xa7320) #51 0x7fffd529021c in __CFRunLoopDoSources0 (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation:x86_64h+0x8821c) #52 0x7fffd528f715 in __CFRunLoopRun (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation:x86_64h+0x87715) #53 0x7fffd528f113 in CFRunLoopRunSpecific (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation:x86_64h+0x87113) #54 0x7fffd47efebb in RunCurrentEventLoopInMode (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox:x86_64+0x30ebb) #55 0x7fffd47efcf0 in ReceiveNextEventCommon (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox:x86_64+0x30cf0) #56 0x7fffd47efb25 in _BlockUntilNextEventMatchingListInModeWithFilter (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox:x86_64+0x30b25) #57 0x7fffd2d88a53 in _DPSNextEvent (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit:x86_64+0x46a53) #58 0x7fffd35047ed in -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit:x86_64+0x7c27ed) #59 0x7fffd2d7d3da in -[NSApplication run] (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit:x86_64+0x3b3da) #60 0x7fffd2d47e0d in NSApplicationMain (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit:x86_64+0x5e0d) #61 0x7fffeac688c6 in _xpc_objc_main (/usr/lib/system/libxpc.dylib:x86_64+0x108c6) #62 0x7fffeac672e3 in xpc_main (/usr/lib/system/libxpc.dylib:x86_64+0xf2e3) #63 0x1008d656c in main (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent.Development:x86_64+0x10000156c) #64 0x7fffeaa0f234 in start (/usr/lib/system/libdyld.dylib:x86_64+0x5234) 0x607000149b24 is located 20 bytes inside of 72-byte region [0x607000149b10,0x607000149b58) freed by thread T0 here: #0 0x103b3c294 in __sanitizer_mz_free (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.1.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib:x86_64h+0x57294) #1 0x108b74650 in bmalloc::Deallocator::deallocateSlowCase(void*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1d72650) #2 0x10ff7685f in WebCore::ContainerNode::removeChildren() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x3ce85f) #3 0x111d1b663 in WebCore::replaceChildrenWithFragment(WebCore::ContainerNode&, WTF::Ref<WebCore::DocumentFragment>&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x2173663) #4 0x1104ff36b in WebCore::Element::setInnerHTML(WTF::String const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x95736b) #5 0x1111ca534 in WebCore::setJSElementInnerHTMLSetter(JSC::ExecState&, WebCore::JSElement&, JSC::JSValue, JSC::ThrowScope&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x1622534) #6 0x1111bbca7 in bool WebCore::IDLAttribute<WebCore::JSElement>::set<&(WebCore::setJSElementInnerHTMLSetter(JSC::ExecState&, WebCore::JSElement&, JSC::JSValue, JSC::ThrowScope&)), (WebCore::CastedThisErrorBehavior)0>(JSC::ExecState&, long long, long long, char const*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x1613ca7) #7 0x1077b0e48 in JSC::callCustomSetter(JSC::ExecState*, bool (*)(JSC::ExecState*, long long, long long), bool, JSC::JSValue, JSC::JSValue) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x9aee48) #8 0x1077b0f77 in JSC::callCustomSetter(JSC::ExecState*, JSC::JSValue, bool, JSC::JSObject*, JSC::JSValue, JSC::JSValue) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x9aef77) #9 0x1082b5008 in JSC::JSObject::putInlineSlow(JSC::ExecState*, JSC::PropertyName, JSC::JSValue, JSC::PutPropertySlot&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x14b3008) #10 0x10848b655 in llint_slow_path_put_by_id (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1689655) #11 0x1084a94f4 in llint_entry (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x16a74f4) #12 0x1084ace49 in llint_entry (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x16aae49) #13 0x1084a5f6f in vmEntryToJavaScript (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x16a3f6f) #14 0x108109847 in JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1307847) #15 0x10808a88a in JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x128888a) #16 0x1076a3731 in JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x8a1731) #17 0x1076a39a2 in JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x8a19a2) #18 0x1076a3d13 in JSC::profiledCall(JSC::ExecState*, JSC::ProfilingReason, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x8a1d13) #19 0x110de6615 in WebCore::JSMainThreadExecState::profiledCall(JSC::ExecState*, JSC::ProfilingReason, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x123e615) #20 0x1111f96cd in WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&, WebCore::Event&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x16516cd) #21 0x110565010 in WebCore::EventTarget::fireEventListeners(WebCore::Event&, WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener>, 1ul, WTF::CrashOnOverflow, 16ul>) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x9bd010) #22 0x110564ae0 in WebCore::EventTarget::fireEventListeners(WebCore::Event&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x9bcae0) #23 0x110442051 in WebCore::DOMWindow::dispatchEvent(WebCore::Event&, WebCore::EventTarget*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x89a051) #24 0x110451c0f in WebCore::DOMWindow::dispatchLoadEvent() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x8a9c0f) #25 0x110344b0f in WebCore::Document::dispatchWindowLoadEvent() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x79cb0f) #26 0x11033ebad in WebCore::Document::implicitClose() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x796bad) #27 0x1106f13ed in WebCore::FrameLoader::checkCompleted() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xb493ed) #28 0x1106ee75c in WebCore::FrameLoader::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xb4675c) #29 0x11035e523 in WebCore::Document::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x7b6523) previously allocated by thread T0 here: #0 0x103b3bd2c in __sanitizer_mz_malloc (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.1.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib:x86_64h+0x56d2c) #1 0x7fffeab91281 in malloc_zone_malloc (/usr/lib/system/libsystem_malloc.dylib:x86_64+0x2281) #2 0x108b74ad4 in bmalloc::DebugHeap::malloc(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1d72ad4) #3 0x108b72d6d in bmalloc::Allocator::allocateSlowCase(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1d70d6d) #4 0x108af9247 in bmalloc::Allocator::allocate(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1cf7247) #5 0x108af863a in WTF::fastMalloc(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore:x86_64+0x1cf663a) #6 0x10fcee648 in WebCore::Node::operator new(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x146648) #7 0x112acdaad in WebCore::Text::create(WebCore::Document&, WTF::String const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x2f25aad) #8 0x112acf4f8 in WebCore::Text::createWithLengthLimit(WebCore::Document&, WTF::String const&, unsigned int, unsigned int) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x2f274f8) #9 0x1108b911b in WebCore::HTMLConstructionSite::insertTextNode(WTF::String const&, WebCore::WhitespaceMode) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xd1111b) #10 0x110a2521f in WebCore::HTMLTreeBuilder::processCharacterBufferForInBody(WebCore::HTMLTreeBuilder::ExternalCharacterTokenBuffer&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xe7d21f) #11 0x110a1f223 in WebCore::HTMLTreeBuilder::processCharacterBuffer(WebCore::HTMLTreeBuilder::ExternalCharacterTokenBuffer&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xe77223) #12 0x110a1e083 in WebCore::HTMLTreeBuilder::processCharacter(WebCore::AtomicHTMLToken&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xe76083) #13 0x110a1ad0e in WebCore::HTMLTreeBuilder::constructTree(WebCore::AtomicHTMLToken&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xe72d0e) #14 0x1108e3c8a in WebCore::HTMLDocumentParser::constructTreeFromHTMLToken(WebCore::HTMLTokenizer::TokenPtr&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xd3bc8a) #15 0x1108e3849 in WebCore::HTMLDocumentParser::pumpTokenizerLoop(WebCore::HTMLDocumentParser::SynchronousMode, bool, WebCore::PumpSession&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xd3b849) #16 0x1108e29c2 in WebCore::HTMLDocumentParser::pumpTokenizer(WebCore::HTMLDocumentParser::SynchronousMode) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xd3a9c2) #17 0x1108e44e8 in WebCore::HTMLDocumentParser::append(WTF::RefPtr<WTF::StringImpl>&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xd3c4e8) #18 0x1102c2531 in WebCore::DecodedDataDocumentParser::flush(WebCore::DocumentWriter&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x71a531) #19 0x1103ff63d in WebCore::DocumentWriter::end() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x85763d) #20 0x1103c0736 in WebCore::DocumentLoader::finishedLoading() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x818736) #21 0x10fe3c047 in WebCore::CachedResource::checkNotify() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x294047) #22 0x10fe34df1 in WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x28cdf1) #23 0x11290c661 in WebCore::SubresourceLoader::didFinishLoading(WebCore::NetworkLoadMetrics const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0x2d64661) #24 0x10140243b in WebKit::WebResourceLoader::didFinishResourceLoad(WebCore::NetworkLoadMetrics const&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xb1343b) #25 0x1014056d9 in void IPC::handleMessage<Messages::WebResourceLoader::DidFinishResourceLoad, WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)>(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xb166d9) #26 0x101404bc9 in WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xb15bc9) #27 0x100bf6117 in WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0x307117) #28 0x1009d5695 in IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xe6695) #29 0x1009dea48 in IPC::Connection::dispatchOneMessage() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit:x86_64+0xefa48) SUMMARY: AddressSanitizer: heap-use-after-free (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore:x86_64+0xa029) in WebCore::Node::getFlag(WebCore::Node::NodeFlags) const Shadow bytes around the buggy address: 0x1c0e00029310: fd fd fd fd fd fd fd fa fa fa fa fa 00 00 00 00 0x1c0e00029320: 00 00 00 00 00 fa fa fa fa fa fd fd fd fd fd fd 0x1c0e00029330: fd fd fd fd fa fa fa fa 00 00 00 00 00 00 00 00 0x1c0e00029340: 00 fa fa fa fa fa 00 00 00 00 00 00 00 00 00 00 0x1c0e00029350: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 fa fa =>0x1c0e00029360: fa fa fd fd[fd]fd fd fd fd fd fd fa fa fa fa fa 0x1c0e00029370: 00 00 00 00 00 00 00 00 00 fa fa fa fa fa 00 00 0x1c0e00029380: 00 00 00 00 00 00 00 fa fa fa fa fa fd fd fd fd 0x1c0e00029390: fd fd fd fd fd fa fa fa fa fa fd fd fd fd fd fd 0x1c0e000293a0: fd fd fd fa fa fa fa fa fd fd fd fd fd fd fd fd 0x1c0e000293b0: fd fd fa fa fa fa fd fd fd fd fd fd fd fd fd fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==29700==ABORTING ```