It first showed up in 22.0a1/20130322. The regression range is: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=a73a2b5c423b&tochange=0e9badd3cf39 It's likely a regression from bug 830267. Signature nsCOMPtr_base::assign_assuming_AddRef(nsISupports*) | nsPluginHost::ReadPluginInfo() More Reports Search UUID 9e747112-a520-446d-83db-fe9232130322 Date Processed 2013-03-22 16:38:27 Uptime 6 Last Crash 29 seconds before submission Install Age 4.0 minutes since version was first installed. Install Time 2013-03-22 16:34:30 Product Firefox Version 22.0a1 Build ID 20130322031028 Release Channel nightly OS Windows NT OS Version 6.1.7601 Service Pack 1 Build Architecture x86 Build Architecture Info GenuineIntel family 6 model 23 stepping 10 Crash Reason EXCEPTION_ACCESS_VIOLATION_READ Crash Address 0x30 App Notes AdapterVendorID: 0x10de, AdapterDeviceID: 0x0641, AdapterSubsysID: 00000000, AdapterDriverVersion: 8.16.11.9107 D3D10 Layers? D3D10 Layers- Processor Notes sp-processor08.phx1.mozilla.com_14835:2008 EMCheckCompatibility True Adapter Vendor ID 0x10de Adapter Device ID 0x0641 Total Virtual Memory 2147352576 Available Virtual Memory 1888141312 System Memory Use Percentage 52 Available Page File 2246787072 Available Physical Memory 1011781632 Frame Module Signature Source 0 xul.dll nsCOMPtr_base::assign_assuming_AddRef obj-firefox/dist/include/nsCOMPtr.h:437 1 xul.dll nsPluginHost::ReadPluginInfo dom/plugins/base/nsPluginHost.cpp:2610 2 xul.dll nsPluginHost::UpdatePluginInfo dom/plugins/base/nsPluginHost.cpp:2361 3 xul.dll nsPluginTag::SetEnabled dom/plugins/base/nsPluginTags.cpp:347 4 xul.dll nsPluginTag::SetDisabled dom/plugins/base/nsPluginTags.cpp:360 5 xul.dll nsPluginHost::ScanPluginsDirectory dom/plugins/base/nsPluginHost.cpp:2041 6 xul.dll nsPluginHost::ScanPluginsDirectoryList dom/plugins/base/nsPluginHost.cpp:2147 7 xul.dll nsPluginHost::FindPlugins dom/plugins/base/nsPluginHost.cpp:2255 8 xul.dll nsPluginHost::LoadPlugins dom/plugins/base/nsPluginHost.cpp:2175 9 xul.dll nsPluginHost::GetPluginTags dom/plugins/base/nsPluginHost.cpp:1345 10 xul.dll NS_InvokeByIndex_P xpcom/reflect/xptcall/src/md/win32/xptcinvoke.cpp:70 11 xul.dll XPC_WN_CallMethod js/xpconnect/src/XPCWrappedNativeJSOps.cpp:1417 12 mozjs.dll js::InvokeKernel js/src/jsinterp.cpp:384 13 mozjs.dll js::Interpret js/src/jsinterp.cpp:2396 14 mozjs.dll js::RunScript js/src/jsinterp.cpp:333 15 mozjs.dll js::InvokeKernel js/src/jsinterp.cpp:398 16 mozjs.dll js::Invoke js/src/jsinterp.cpp:431 17 mozjs.dll JS_CallFunctionValue js/src/jsapi.cpp:5769 18 xul.dll nsXPCWrappedJSClass::CallMethod js/xpconnect/src/XPCWrappedJSClass.cpp:1433 19 xul.dll nsXPCWrappedJS::CallMethod js/xpconnect/src/XPCWrappedJS.cpp:578 20 xul.dll PrepareAndDispatch xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:85 21 xul.dll SharedStub xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:112 22 xul.dll nsObserverService::NotifyObservers xpcom/ds/nsObserverService.cpp:161 More reports at: https://crash-stats.mozilla.com/report/list?signature=nsCOMPtr_base%3A%3Aassign_assuming_AddRef%28nsISupports*%29+|+nsPluginHost%3A%3AReadPluginInfo%28%29 https://crash-stats.mozilla.com/report/list?signature=nsCOMPtr_base%3A%3Aassign_assuming_AddRef%28nsISupports*%29+|+nsCOMPtr%3CnsIScriptRuntime%3E%3A%3AStartAssignment%28%29+|+nsPluginHost%3A%3AReadPluginInfo%28%29

I can get this to reproduce reliably under OS X with the Adobe PDF plugin installed. In particular, the crash arises when trying to deal with AdobePDFViewerNPAPI.plugin

I can also confirm that the problem does not arise on mozilla-incoming rev 125721, and does happen for mozilla-incoming rev 125722, which confirms the theory that the problem is caused by the patch for bug 830267.

mPluginHost is null here: http://hg.mozilla.org/mozilla-central/annotate/0e9badd3cf39/dom/plugins/base/nsPluginTags.cpp#l347 Why do we even bother with mPluginHost instead of just using nsPluginHost::GetInst ?

It's #2 top crasher in 22.0a1/20130322.

Good question regarding nsPluginTag::mPluginHost, i don't see any reason to keep it over nsPluginHost::GetInst(). https://tbpl.mozilla.org/?tree=Try&rev=48da68e17899

I get this crash consistently in XP with no Adobe Reader; Foxit Reader is installed, but plugin disabled in favor of pdf.js. Also crashes in Safe Mode, or with a new, clean profile. However, with a clean test profile I already had on hand there's no crash. In this profile, the Foxit Reader plugin is enabled. Don't know if this helps, but it's certainly interesting. Here's a couple crash reports, in case they might be helpful: https://crash-stats.mozilla.com/report/index/bp-e016e4ef-8ff2-45be-a559-fde372130323 https://crash-stats.mozilla.com/report/index/bp-ce72a43e-df3e-4d8e-b572-37dbb2130323

On the most recent nightly, I crash immediately every time visiting https://blog.mozilla.org/luke.

More generally, on OSX, Nightly randomly on many different pages, about:addons, on every quit, etc, making Nightly completely unusable. This problem just started in one of the last one or two nightlies; is there something we can back out?

RE #7 - Tried enabling Foxit Reader plugin and setting option to use foxit plugin for PDFs in my regular Nightly profile. Didn't help, still crashed.

(In reply to Luke Wagner [:luke] from comment #9) > This > problem just started in one of the last one or two nightlies; is there > something we can back out? This is due to bug 830267, but the patch here should take care of it.

I'm mostly knocked out by a viral infection, so i'd appreciate a check-in in case of r+.