304651 2025-12-23 12:09:52 -0800 REGRESSION(304792@main?): [macOS iOS] Flaky crash in site-isolation tests 2026-01-09 11:07:11 -0800 1 1 1 Unclassified WebKit New Bugs WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 darbinyan kiet.ho webkit-bot-watchers-bugzilla webkit-bug-importer oldest_to_newest 2167984 0 darbinyan 2025-12-23 12:09:52 -0800 There are intermittenly crashing layout tests in site-isolation both in macOS and iOS. The tests are also flaky in EWS across different PRs. http/tests/site-isolation/history/add-iframes-and-navigate-mainframe.html http/tests/site-isolation/focus-click-navigation-activeElement.html http/tests/site-isolation/history/add-iframes-and-go-back.html Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 com.apple.WebKit 0x105840e74 WebKit::WebPageProxy::broadcastFrameTreeSyncData(IPC::Connection&, WTF::ObjectIdentifierGeneric<WebCore::FrameIdentifierType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long long>, unsigned long long>, WebCore::FrameTreeSyncSerializationData const&) 1 com.apple.WebKit 0x1052aa2d0 WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 2 com.apple.WebKit 0x105dd4c6c IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) 3 com.apple.WebKit 0x1058ce084 WebKit::WebProcessProxy::dispatchMessage(IPC::Connection&, IPC::Decoder&) 4 com.apple.WebKit 0x10532e46c WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 5 com.apple.WebKit 0x105dce600 IPC::Connection::dispatchMessage(IPC::Decoder&) 6 com.apple.WebKit 0x105dce7c0 IPC::Connection::dispatchMessage(WTF::UniqueRef<IPC::Decoder>) 7 com.apple.WebKit 0x105dced68 IPC::Connection::dispatchIncomingMessages() 8 com.apple.JavaScriptCore 0x10a8e70c4 WTF::RunLoop::performWork() 9 com.apple.JavaScriptCore 0x10a8e8800 WTF::RunLoop::performWork(void*) 10 com.apple.CoreFoundation 0x191ac94b8 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 /AppleInternal/Library/BuildRoots/b0c24a1e-bd47-11ef-bf9c-aabfac210453/Library/Caches/com.apple.xbs/Sources/CoreFoundation/CoreFoundation/RunLoop.subproj/CFRunLoop.c:1957 11 com.apple.CoreFoundation 0x191ac944c __CFRunLoopDoSource0 + 176 /AppleInternal/Library/BuildRoots/b0c24a1e-bd47-11ef-bf9c-aabfac210453/Library/Caches/com.apple.xbs/Sources/CoreFoundation/CoreFoundation/RunLoop.subproj/CFRunLoop.c:2001 12 com.apple.CoreFoundation 0x191ac91bc __CFRunLoopDoSources0 + 244 /AppleInternal/Library/BuildRoots/b0c24a1e-bd47-11ef-bf9c-aabfac210453/Library/Caches/com.apple.xbs/Sources/CoreFoundation/CoreFoundation/RunLoop.subproj/CFRunLoop.c:2038 13 com.apple.CoreFoundation 0x191ac7da8 __CFRunLoopRun + 828 /AppleInternal/Library/BuildRoots/b0c24a1e-bd47-11ef-bf9c-aabfac210453/Library/Caches/com.apple.xbs/Sources/CoreFoundation/CoreFoundation/RunLoop.subproj/CFRunLoop.c:2955 14 com.apple.CoreFoundation 0x191ac7414 CFRunLoopRunSpecific + 608 /AppleInternal/Library/BuildRoots/b0c24a1e-bd47-11ef-bf9c-aabfac210453/Library/Caches/com.apple.xbs/Sources/CoreFoundation/CoreFoundation/RunLoop.subproj/CFRunLoop.c:3420 15 com.apple.Foundation 0x192bfc868 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 212 /AppleInternal/Library/BuildRoots/558fc4d6-d024-11ef-9ee2-d285688f7a47/Library/Caches/com.apple.xbs/Sources/Foundation/Foundation/Soil.subproj/NSRunLoop.m:373 16 WebKitTestRunner 0x1047ac238 WTR::TestController::platformRunUntil(bool&, WTF::Seconds) 17 WebKitTestRunner 0x10478c290 WTR::TestController::resetStateToConsistentValues(WTR::TestOptions const&, WTR::TestController::ResetStage)::$_13::operator()() const 18 WebKitTestRunner 0x10478b784 WTR::TestController::resetStateToConsistentValues(WTR::TestOptions const&, WTR::TestController::ResetStage) 19 WebKitTestRunner 0x1047b9cd8 WTR::TestInvocation::invoke() 20 WebKitTestRunner 0x104790d8c WTR::TestController::runTest(char const*) 21 WebKitTestRunner 0x104791170 WTR::TestController::runTestingServerLoop() 22 WebKitTestRunner 0x104785144 WTR::TestController::TestController(int, char const**) 23 WebKitTestRunner 0x104763098 main 24 dyld 0x19165f154 start + 2476 /AppleInternal/Library/BuildRoots/558fc4d6-d024-11ef-9ee2-d285688f7a47/Library/Caches/com.apple.xbs/Sources/dyld/dyld/dyldMain.cpp:1298 Test results: https://build.webkit.org/#/builders/1702/builds/645 History: https://results.webkit.org/?suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&test=http%2Ftests%2Fsite-isolation%2Fhistory%2Fadd-iframes-and-go-back.html&test=http%2Ftests%2Fsite-isolation%2Ffocus-click-navigation-activeElement.html&test=http%2Ftests%2Fsite-isolation%2Fhistory%2Fadd-iframes-and-navigate-mainframe.html&test=http%2Ftests%2Fsite-isolation%2Fhistory%2Fadd-iframes-and-go-back.html&style=release 2167985 1 webkit-bug-importer 2025-12-23 12:10:20 -0800 <rdar://problem/167097502> 2167994 2 ews-feeder 2025-12-23 12:57:56 -0800 Test gardening commit 304909@main (22206fe1f4d0): <https://commits.webkit.org/304909@main> Reviewed commits have been landed. Closing PR #55837 and removing active labels. 2170349 3 kiet.ho 2026-01-08 10:57:12 -0800 Pull request: https://github.com/WebKit/WebKit/pull/56270 2170723 4 ews-feeder 2026-01-09 11:07:09 -0800 Committed 305370@main (5583c5d63e5e): <https://commits.webkit.org/305370@main> Reviewed commits have been landed. Closing PR #56270 and removing active labels.