WebKit: UXSS via Editor::Command::execute CVE-2017-2504 Here's a snippet of Editor::Command::execute used to handle |document.execCommand|. bool Editor::Command::execute(const String& parameter, Event* triggeringEvent) const { if (!isEnabled(triggeringEvent)) { // Let certain commands be executed when performed explicitly even if they are disabled. if (!allowExecutionWhenDisabled()) return false; } m_frame->document()->updateLayoutIgnorePendingStylesheets(); return m_command->execute(*m_frame, triggeringEvent, m_source, parameter); } This method is invoked under an |EventQueueScope|. But |updateLayoutIgnorePendingStylesheets| invokes |MediaQueryMatcher::styleResolverChanged| that directly calls |handleEvent| not affected by |EventQueueScope|. So it may end up to fire javascript handlers(|listener| in PoC). If we replace the document in that handler, |m_command| will be executed on the new document's focused element. We can use # in URL to give a focus. Note 1: The PoC also trigger a UAF. So I recommend to test it on a release build. Note 2: If the PoC doesn't work, adjust sleep(). Tested on Safari 10.0.3(12602.4.8). PoC: Click Anywhere. UAF Asan Log: ================================================================= ==3526==ERROR: AddressSanitizer: heap-use-after-free on address 0x61700004d1d8 at pc 0x000117706e8b bp 0x7fff5349d050 sp 0x7fff5349d048 READ of size 8 at 0x61700004d1d8 thread T0 #0 0x117706e8a in WebCore::RenderView::flushAccumulatedRepaintRegion() const (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x2485e8a) #1 0x115959230 in WebCore::Document::updateLayout() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6d8230) #2 0x11595f6fb in WebCore::Document::updateLayoutIgnorePendingStylesheets(WebCore::Document::RunPostLayoutTasks) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6de6fb) #3 0x115ae7206 in WebCore::Element::offsetLeft() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x866206) #4 0x11661b82b in WebCore::jsElementOffsetLeftGetter(JSC::ExecState&, WebCore::JSElement&, JSC::ThrowScope&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x139a82b) #5 0x116609fe3 in long long WebCore::BindingCaller::attribute<&(WebCore::jsElementOffsetLeftGetter(JSC::ExecState&, WebCore::JSElement&, JSC::ThrowScope&)), (WebCore::CastedThisErrorBehavior)0>(JSC::ExecState*, long long, char const*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x1388fe3) #6 0x112c20808 in JSC::PropertySlot::customGetter(JSC::ExecState*, JSC::PropertyName) const (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x1588808) #7 0x1129593be in llint_slow_path_get_by_id (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x12c13be) #8 0x1129767b6 in llint_entry (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x12de7b6) #9 0x11297395a in vmEntryToJavaScript (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x12db95a) #10 0x11262d662 in JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0xf95662) #11 0x1125b12f8 in JSC::Interpreter::executeProgram(JSC::SourceCode const&, JSC::ExecState*, JSC::JSObject*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0xf192f8) #12 0x111d90a8c in JSC::evaluate(JSC::ExecState*, JSC::SourceCode const&, JSC::JSValue, WTF::NakedPtr&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x6f8a8c) #13 0x111d90c8e in JSC::profiledEvaluate(JSC::ExecState*, JSC::ProfilingReason, JSC::SourceCode const&, JSC::JSValue, WTF::NakedPtr&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x6f8c8e) #14 0x1177db273 in WebCore::JSMainThreadExecState::profiledEvaluate(JSC::ExecState*, JSC::ProfilingReason, JSC::SourceCode const&, JSC::JSValue, WTF::NakedPtr&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x255a273) #15 0x1177dade4 in WebCore::ScriptController::evaluateInWorld(WebCore::ScriptSourceCode const&, WebCore::DOMWrapperWorld&, WebCore::ExceptionDetails*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x2559de4) #16 0x1177ee9d1 in WebCore::ScriptElement::executeClassicScript(WebCore::ScriptSourceCode const&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x256d9d1) #17 0x1177eb9ba in WebCore::ScriptElement::prepareScript(WTF::TextPosition const&, WebCore::ScriptElement::LegacyTypeSupport) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x256a9ba) #18 0x115f62940 in WebCore::HTMLScriptRunner::runScript(WebCore::ScriptElement&, WTF::TextPosition const&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xce1940) #19 0x115f62685 in WebCore::HTMLScriptRunner::execute(WTF::Ref&&, WTF::TextPosition const&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xce1685) #20 0x115e83cae in WebCore::HTMLDocumentParser::runScriptsForPausedTreeBuilder() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc02cae) #21 0x115e84392 in WebCore::HTMLDocumentParser::pumpTokenizerLoop(WebCore::HTMLDocumentParser::SynchronousMode, bool, WebCore::PumpSession&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc03392) #22 0x115e835c4 in WebCore::HTMLDocumentParser::pumpTokenizer(WebCore::HTMLDocumentParser::SynchronousMode) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc025c4) #23 0x115e84fbd in WebCore::HTMLDocumentParser::append(WTF::RefPtr&&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc03fbd) #24 0x1158dfde1 in WebCore::DecodedDataDocumentParser::flush(WebCore::DocumentWriter&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x65ede1) #25 0x115a125b8 in WebCore::DocumentWriter::end() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7915b8) #26 0x1159d5a6e in WebCore::DocumentLoader::finishedLoading(double) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x754a6e) #27 0x1154dc8c7 in WebCore::CachedResource::checkNotify() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x25b8c7) #28 0x1154d623d in WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x25523d) #29 0x117afd1eb in WebCore::SubresourceLoader::didFinishLoading(double) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x287c1eb) #30 0x10f774825 in WebKit::WebResourceLoader::didFinishResourceLoad(double) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x996825) #31 0x10f777c05 in void IPC::handleMessage(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(double)) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x999c05) #32 0x10f7770ff in WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x9990ff) #33 0x10f0b75c9 in WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x2d95c9) #34 0x10ee925a8 in IPC::Connection::dispatchMessage(std::__1::unique_ptr >) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xb45a8) #35 0x10ee9bbf4 in IPC::Connection::dispatchOneMessage() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xbdbf4) #36 0x112f6c764 in WTF::RunLoop::performWork() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18d4764) #37 0x112f6ec7e in WTF::RunLoop::performWork(void*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18d6c7e) #38 0x7fff7dcc3980 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0xa7980) #39 0x7fff7dca4a7c in __CFRunLoopDoSources0 (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x88a7c) #40 0x7fff7dca3f75 in __CFRunLoopRun (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x87f75) #41 0x7fff7dca3973 in CFRunLoopRunSpecific (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x87973) #42 0x7fff7d22fa5b in RunCurrentEventLoopInMode (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox+0x30a5b) #43 0x7fff7d22f890 in ReceiveNextEventCommon (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox+0x30890) #44 0x7fff7d22f6c5 in _BlockUntilNextEventMatchingListInModeWithFilter (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox+0x306c5) #45 0x7fff7b7d55b3 in _DPSNextEvent (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x475b3) #46 0x7fff7bf4fd6a in -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x7c1d6a) #47 0x7fff7b7c9f34 in -[NSApplication run] (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x3bf34) #48 0x7fff7b79484f in NSApplicationMain (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit+0x684f) #49 0x7fff9345f8c6 in _xpc_objc_main (/usr/lib/system/libxpc.dylib+0x108c6) #50 0x7fff9345e2e3 in xpc_main (/usr/lib/system/libxpc.dylib+0xf2e3) #51 0x10c75db73 in main (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent.Development+0x100001b73) #52 0x7fff931fb254 in start (/usr/lib/system/libdyld.dylib+0x5254) 0x61700004d1d8 is located 344 bytes inside of 720-byte region [0x61700004d080,0x61700004d350) freed by thread T0 here: #0 0x10c7bdcf4 in __sanitizer_mz_free (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.0.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib+0x4bcf4) #1 0x112fb56bf in bmalloc::Deallocator::deallocateSlowCase(void*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x191d6bf) #2 0x11599f26f in WebCore::RenderPtr::clear() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x71e26f) #3 0x11596212d in WebCore::RenderPtr::operator=(std::nullptr_t) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6e112d) #4 0x115961ce0 in WebCore::Document::destroyRenderTree() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6e0ce0) #5 0x1159622e2 in WebCore::Document::prepareForDestruction() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6e12e2) #6 0x115cbef2a in WebCore::Frame::setView(WTF::RefPtr&&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa3df2a) #7 0x115cc1ed4 in WebCore::Frame::createView(WebCore::IntSize const&, WebCore::Color const&, bool, WebCore::IntSize const&, WebCore::IntRect const&, bool, WebCore::ScrollbarMode, bool, WebCore::ScrollbarMode, bool) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa40ed4) #8 0x10f40a85b in WebKit::WebFrameLoaderClient::transitionToCommittedForNewPage() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x62c85b) #9 0x115cd84bf in WebCore::FrameLoader::transitionToCommitted(WebCore::CachedPage*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa574bf) #10 0x115cd7593 in WebCore::FrameLoader::commitProvisionalLoad() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa56593) #11 0x1159d59cc in WebCore::DocumentLoader::finishedLoading(double) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7549cc) #12 0x1159ddc2e in WebCore::DocumentLoader::maybeLoadEmpty() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x75cc2e) #13 0x1159de008 in WebCore::DocumentLoader::startLoadingMainResource() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x75d008) #14 0x115cdb9f1 in WebCore::FrameLoader::continueLoadAfterWillSubmitForm() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa5a9f1) #15 0x115cd5433 in WebCore::FrameLoader::continueLoadAfterNavigationPolicy(WebCore::ResourceRequest const&, WebCore::FormState*, bool, WebCore::AllowNavigationToInvalidURL) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa54433) #16 0x117283965 in std::__1::function::operator()(WebCore::ResourceRequest const&, WebCore::FormState*, bool) const (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x2002965) #17 0x1172837bf in WebCore::PolicyCallback::call(bool) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x20027bf) #18 0x11728511a in WebCore::PolicyChecker::continueAfterNavigationPolicy(WebCore::PolicyAction) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x200411a) #19 0x10f3f49ee in std::__1::function::operator()(WebCore::PolicyAction) const (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x6169ee) #20 0x10f3f4846 in WebKit::WebFrame::didReceivePolicyDecision(unsigned long long, WebCore::PolicyAction, unsigned long long, WebKit::DownloadID) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x616846) #21 0x10f40494d in WebKit::WebFrameLoaderClient::dispatchDecidePolicyForNavigationAction(WebCore::NavigationAction const&, WebCore::ResourceRequest const&, WebCore::FormState*, std::__1::function) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x62694d) #22 0x117284bb9 in WebCore::PolicyChecker::checkNavigationPolicy(WebCore::ResourceRequest const&, bool, WebCore::DocumentLoader*, WebCore::FormState*, std::__1::function) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x2003bb9) #23 0x115cd413c in WebCore::FrameLoader::loadWithDocumentLoader(WebCore::DocumentLoader*, WebCore::FrameLoadType, WebCore::FormState*, WebCore::AllowNavigationToInvalidURL) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa5313c) #24 0x115cd2e76 in WebCore::FrameLoader::loadWithNavigationAction(WebCore::ResourceRequest const&, WebCore::NavigationAction const&, WebCore::LockHistory, WebCore::FrameLoadType, WebCore::FormState*, WebCore::AllowNavigationToInvalidURL) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa51e76) #25 0x115ccf7a1 in WebCore::FrameLoader::loadURL(WebCore::FrameLoadRequest const&, WTF::String const&, WebCore::FrameLoadType, WebCore::Event*, WebCore::FormState*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa4e7a1) #26 0x115cc8af0 in WebCore::FrameLoader::loadFrameRequest(WebCore::FrameLoadRequest const&, WebCore::Event*, WebCore::FormState*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa47af0) #27 0x115cc8079 in WebCore::FrameLoader::urlSelected(WebCore::FrameLoadRequest const&, WebCore::Event*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa47079) #28 0x115cc82fa in WebCore::FrameLoader::urlSelected(WebCore::URL const&, WTF::String const&, WebCore::Event*, WebCore::LockHistory, WebCore::LockBackForwardList, WebCore::ShouldSendReferrer, WebCore::ShouldOpenExternalURLsPolicy, std::optional, WTF::AtomicString const&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa472fa) #29 0x115e39f39 in WebCore::HTMLAnchorElement::handleClick(WebCore::Event&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xbb8f39) previously allocated by thread T0 here: #0 0x10c7bd790 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 0x7fff9337d2d9 in malloc_zone_malloc (/usr/lib/system/libsystem_malloc.dylib+0x22d9) #2 0x112fbf184 in bmalloc::DebugHeap::malloc(unsigned long) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x1927184) #3 0x112fb447b in bmalloc::Allocator::allocateSlowCase(unsigned long) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x191c47b) #4 0x112f4d245 in bmalloc::Allocator::allocate(unsigned long) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18b5245) #5 0x112f4c528 in WTF::fastMalloc(unsigned long) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18b4528) #6 0x11596140d in WebCore::RenderPtr WebCore::createRenderer(WebCore::Document&&&, WebCore::RenderStyle&&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6e040d) #7 0x1159611ed in WebCore::Document::createRenderTree() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6e01ed) #8 0x115961519 in WebCore::Document::didBecomeCurrentDocumentInFrame() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6e0519) #9 0x115cbf910 in WebCore::Frame::setDocument(WTF::RefPtr&&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa3e910) #10 0x115a11f94 in WebCore::DocumentWriter::begin(WebCore::URL const&, bool, WebCore::Document*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x790f94) #11 0x1159d6365 in WebCore::DocumentLoader::commitData(char const*, unsigned long) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x755365) #12 0x10f406052 in WebKit::WebFrameLoaderClient::committedLoad(WebCore::DocumentLoader*, char const*, int) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x628052) #13 0x1159d995c in WebCore::DocumentLoader::commitLoad(char const*, int) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x75895c) #14 0x1154d5eff in WebCore::CachedRawResource::notifyClientsDataWasReceived(char const*, unsigned int) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x254eff) #15 0x1154d5cf5 in WebCore::CachedRawResource::addDataBuffer(WebCore::SharedBuffer&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x254cf5) #16 0x117afe96c in WebCore::SubresourceLoader::didReceiveDataOrBuffer(char const*, int, WTF::RefPtr&&, long long, WebCore::DataPayloadType) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x287d96c) #17 0x117afe695 in WebCore::SubresourceLoader::didReceiveData(char const*, unsigned int, long long, WebCore::DataPayloadType) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x287d695) #18 0x10f7740b5 in WebKit::WebResourceLoader::didReceiveData(IPC::DataReference const&, long long) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x9960b5) #19 0x10f777ab4 in void IPC::handleMessage(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(IPC::DataReference const&, long long)) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x999ab4) #20 0x10f777043 in WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x999043) #21 0x10f0b75c9 in WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x2d95c9) #22 0x10ee925a8 in IPC::Connection::dispatchMessage(std::__1::unique_ptr >) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xb45a8) #23 0x10ee9bbf4 in IPC::Connection::dispatchOneMessage() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xbdbf4) #24 0x112f6c764 in WTF::RunLoop::performWork() (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18d4764) #25 0x112f6ec7e in WTF::RunLoop::performWork(void*) (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18d6c7e) #26 0x7fff7dcc3980 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0xa7980) #27 0x7fff7dca4a7c in __CFRunLoopDoSources0 (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x88a7c) #28 0x7fff7dca3f75 in __CFRunLoopRun (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x87f75) #29 0x7fff7dca3973 in CFRunLoopRunSpecific (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x87973) SUMMARY: AddressSanitizer: heap-use-after-free (/Volumes/L/Develop/audits/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x2485e8a) in WebCore::RenderView::flushAccumulatedRepaintRegion() const Shadow bytes around the buggy address: 0x1c2e000099e0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x1c2e000099f0: fd fd fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x1c2e00009a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x1c2e00009a10: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x1c2e00009a20: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd =>0x1c2e00009a30: fd fd fd fd fd fd fd fd fd fd fd[fd]fd fd fd fd 0x1c2e00009a40: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x1c2e00009a50: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x1c2e00009a60: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa 0x1c2e00009a70: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x1c2e00009a80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 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 Heap right redzone: fb Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 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 ==3526==ABORTING This bug is subject to a 90 day disclosure deadline. After 90 days elapse or a patch has been made broadly available, the bug report will become visible to the public. Found by: lokihardt