Found while fuzzing m-c 20210726-0c272222c17b (--enable-debug --enable-fuzzing)

Assertion failure: frame == mFrame (We're referring different frame), at src/layout/painting/nsDisplayList.cpp:5001

#0 0x7fba3e890fb7 in mozilla::nsDisplayCaret::CreateWebRenderCommands(mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&, mozilla::layers::StackingContextHelper const&, mozilla::layers::RenderRootStateManager*, mozilla::nsDisplayListBuilder*) src/layout/painting/nsDisplayList.cpp:5001:3
#1 0x7fba3b0861ff in mozilla::layers::WebRenderCommandBuilder::CreateWebRenderCommands(mozilla::nsDisplayItem*, mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&, mozilla::layers::StackingContextHelper const&, mozilla::nsDisplayListBuilder*) src/gfx/layers/wr/WebRenderCommandBuilder.cpp:1678:41
#2 0x7fba3b084b18 in mozilla::layers::WebRenderCommandBuilder::CreateWebRenderCommandsFromDisplayList(mozilla::nsDisplayList*, mozilla::nsDisplayItem*, mozilla::nsDisplayListBuilder*, mozilla::layers::StackingContextHelper const&, mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&) src/gfx/layers/wr/WebRenderCommandBuilder.cpp:1800:7
#3 0x7fba3e898bbc in CreateWebRenderCommands src/layout/painting/nsDisplayList.cpp:5657:30
#4 0x7fba3e898bbc in mozilla::nsDisplayOwnLayer::CreateWebRenderCommands(mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&, mozilla::layers::StackingContextHelper const&, mozilla::layers::RenderRootStateManager*, mozilla::nsDisplayListBuilder*) src/layout/painting/nsDisplayList.cpp:6454:22
#5 0x7fba3b0861ff in mozilla::layers::WebRenderCommandBuilder::CreateWebRenderCommands(mozilla::nsDisplayItem*, mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&, mozilla::layers::StackingContextHelper const&, mozilla::nsDisplayListBuilder*) src/gfx/layers/wr/WebRenderCommandBuilder.cpp:1678:41
#6 0x7fba3b084b18 in mozilla::layers::WebRenderCommandBuilder::CreateWebRenderCommandsFromDisplayList(mozilla::nsDisplayList*, mozilla::nsDisplayItem*, mozilla::nsDisplayListBuilder*, mozilla::layers::StackingContextHelper const&, mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&) src/gfx/layers/wr/WebRenderCommandBuilder.cpp:1800:7
#7 0x7fba3b083606 in mozilla::layers::WebRenderCommandBuilder::BuildWebRenderCommands(mozilla::wr::DisplayListBuilder&, mozilla::wr::IpcResourceUpdateQueue&, mozilla::nsDisplayList*, mozilla::nsDisplayListBuilder*, mozilla::layers::WebRenderScrollData&, WrFiltersHolder&&) src/gfx/layers/wr/WebRenderCommandBuilder.cpp:1598:5
#8 0x7fba3b0ae154 in mozilla::layers::WebRenderLayerManager::EndTransactionWithoutLayer(mozilla::nsDisplayList*, mozilla::nsDisplayListBuilder*, WrFiltersHolder&&, mozilla::layers::WebRenderBackgroundData*, double) src/gfx/layers/wr/WebRenderLayerManager.cpp:368:30
#9 0x7fba3e8835fe in mozilla::nsDisplayList::PaintRoot(mozilla::nsDisplayListBuilder*, gfxContext*, unsigned int, mozilla::Maybe<double>) src/layout/painting/nsDisplayList.cpp:2536:18
#10 0x7fba3e4ea3e2 in nsLayoutUtils::PaintFrame(gfxContext*, nsIFrame*, nsRegion const&, unsigned int, mozilla::nsDisplayListBuilderMode, nsLayoutUtils::PaintFrameFlags) src/layout/base/nsLayoutUtils.cpp:3542:45
#11 0x7fba3e460e0f in mozilla::PresShell::Paint(nsView*, nsRegion const&, mozilla::PaintFlags) src/layout/base/PresShell.cpp:6406:5
#12 0x7fba3e1037b1 in nsViewManager::ProcessPendingUpdatesPaint(nsIWidget*) src/view/nsViewManager.cpp:459:18
#13 0x7fba3e1032cb in nsViewManager::ProcessPendingUpdatesForView(nsView*, bool) src/view/nsViewManager.cpp:394:22
#14 0x7fba3e10483f in nsViewManager::ProcessPendingUpdates() src/view/nsViewManager.cpp:972:5
#15 0x7fba3e41fb9c in nsRefreshDriver::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsRefreshDriver::IsExtraTick) src/layout/base/nsRefreshDriver.cpp:2473:11
#16 0x7fba3e426e3a in TickDriver src/layout/base/nsRefreshDriver.cpp:348:13
#17 0x7fba3e426e3a in mozilla::RefreshDriverTimer::TickRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&) src/layout/base/nsRefreshDriver.cpp:326:7
#18 0x7fba3e426d53 in mozilla::RefreshDriverTimer::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:342:5
#19 0x7fba3e426c20 in mozilla::VsyncRefreshDriverTimer::RunRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:771:5
#20 0x7fba3e4262ba in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::TickRefreshDriver(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:700:16
#21 0x7fba3e425bd5 in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyParentProcessVsync() src/layout/base/nsRefreshDriver.cpp:617:7
#22 0x7fba3e425659 in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyVsync(mozilla::VsyncEvent const&) src/layout/base/nsRefreshDriver.cpp:538:9
#23 0x7fba3dc39b26 in mozilla::dom::VsyncChild::RecvNotify(mozilla::VsyncEvent const&, float const&) src/dom/ipc/VsyncChild.cpp:68:15
#24 0x7fba3a926784 in mozilla::dom::PVsyncChild::OnMessageReceived(IPC::Message const&) /builds/worker/workspace/obj-build/ipc/ipdl/PVsyncChild.cpp:178:54
#25 0x7fba3a6ee1bc in mozilla::ipc::PBackgroundChild::OnMessageReceived(IPC::Message const&) /builds/worker/workspace/obj-build/ipc/ipdl/PBackgroundChild.cpp:6091:32
#26 0x7fba3a35d181 in mozilla::ipc::MessageChannel::DispatchAsyncMessage(mozilla::ipc::ActorLifecycleProxy*, IPC::Message const&) src/ipc/glue/MessageChannel.cpp:2051:25
#27 0x7fba3a359cc1 in mozilla::ipc::MessageChannel::DispatchMessage(IPC::Message&&) src/ipc/glue/MessageChannel.cpp:1978:9
#28 0x7fba3a35b145 in mozilla::ipc::MessageChannel::RunMessage(mozilla::ipc::MessageChannel::MessageTask&) src/ipc/glue/MessageChannel.cpp:1826:3
#29 0x7fba3a35bcdb in mozilla::ipc::MessageChannel::MessageTask::Run() src/ipc/glue/MessageChannel.cpp:1857:13
#30 0x7fba39a53b1e in mozilla::RunnableTask::Run() src/xpcom/threads/TaskController.cpp:502:16
#31 0x7fba39a31869 in mozilla::TaskController::DoExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) src/xpcom/threads/TaskController.cpp:805:26
#32 0x7fba39a306e8 in mozilla::TaskController::ExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) src/xpcom/threads/TaskController.cpp:641:15
#33 0x7fba39a30963 in mozilla::TaskController::ProcessPendingMTTask(bool) src/xpcom/threads/TaskController.cpp:425:36
#34 0x7fba39a57316 in operator() src/xpcom/threads/TaskController.cpp:135:37
#35 0x7fba39a57316 in mozilla::detail::RunnableFunction<mozilla::TaskController::InitializeInternal()::$_0>::Run() /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:532:5
#36 0x7fba39a4348f in nsThread::ProcessNextEvent(bool, bool*) src/xpcom/threads/nsThread.cpp:1148:16
#37 0x7fba39a49efa in NS_ProcessNextEvent(nsIThread*, bool) src/xpcom/threads/nsThreadUtils.cpp:466:10
#38 0x7fba3a362ff6 in mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:85:21
#39 0x7fba3a2bd8c7 in MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:331:10
#40 0x7fba3a2bd7e2 in RunHandler src/ipc/chromium/src/base/message_loop.cc:324:3
#41 0x7fba3a2bd7e2 in MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:306:3
#42 0x7fba3e14cec8 in nsBaseAppShell::Run() src/widget/nsBaseAppShell.cpp:137:27
#43 0x7fba3fb058e3 in XRE_RunAppShell() src/toolkit/xre/nsEmbedFunctions.cpp:910:20
#44 0x7fba3a363eea in mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:235:9
#45 0x7fba3a2bd8c7 in MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:331:10
#46 0x7fba3a2bd7e2 in RunHandler src/ipc/chromium/src/base/message_loop.cc:324:3
#47 0x7fba3a2bd7e2 in MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:306:3
#48 0x7fba3fb054fe in XRE_InitChildProcess(int, char**, XREChildData const*) src/toolkit/xre/nsEmbedFunctions.cpp:742:34
#49 0x55ef3c8dc9b6 in content_process_main src/browser/app/../../ipc/contentproc/plugin-container.cpp:57:28
#50 0x55ef3c8dc9b6 in main src/browser/app/nsBrowserApp.cpp:327:18
#51 0x7fba4f1190b2 in __libc_start_main /build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:308:16
#52 0x55ef3c8b97bc in _start (/home/worker/builds/m-c-20210726093430-fuzzing-debug/firefox-bin+0x157bc)

A Pernosco session is available here: https://pernos.co/debug/HRSxRcDGjcS2o4u85yL3Ow/index.html

Bugmon Analysis
Verified bug as reproducible on mozilla-central 20210727152622-edce65311704.
The bug appears to have been introduced in the following build range:

Start: f4add6adeb1916d41389d2f94ae3ea5e3b5b14b3 (20210723092513)
End: 95ed028bafe8d8154a2123689fae00420a0f5cc2 (20210723151905)
Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=f4add6adeb1916d41389d2f94ae3ea5e3b5b14b3&tochange=95ed028bafe8d8154a2123689fae00420a0f5cc2

Bugmon was unable reproduce this issue.
Removing bugmon keyword as no further action possible. Please review the bug and re-add the keyword for further analysis.

A change to the Taskcluster build definitions over the weekend caused Bugmon to fail when reproducing issues. This issue has been corrected. Re-enabling bugmon.