Bug 137426 – [X11] Plugin process crashes in NetscapePlugin::platformPostInitialize()

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Michael Catanzaro]

Here's another crash that's been hit a lot in Fedora, a SIGABRT when (presumably) starting Flash:

Downstream report: https://bugzilla.redhat.com/show_bug.cgi?id=1139316
Crash statistics: https://retrace.fedoraproject.org/faf/reports/426221/
Full backtrace: https://bugzilla.redhat.com/attachment.cgi?id=935404

[Michael Catanzaro]

Probably the same as this crash: https://retrace.fedoraproject.org/faf/reports/444412/

[Carlos Garcia Campos]

How can I try to reproduce it? Does it happen for any website having flash?

[Michael Catanzaro]

vrutkovs:  mcatanzaro: sorry, no info, it just happened during the day of F21 usage
mcatanzaro:  vrutkovs: Alas. OK, thanks.
vrutkovs:  my workstation has been doing lots of background tasks recently so it might be one of these race condition bugs
mcatanzaro:  Well there's over 900 reports so it's not just you.

I'll ask in the downstream bug in case someone else has noticed a pattern.

[Carlos Garcia Campos]

I managed to reproduce this, or at least a similar crash, because here it crashes in NetscapePlugin::initialize, like the bt in comment #2. The thing is that flash in crashing in NPP_GetValue when called with NPPVpluginCancelSrcStream.

#0  0x00007f6e52ecb873 in ?? () from /usr/lib/mozilla/plugins/flash-mozilla.so
#1  0x00007f6e5306ed1c in ?? () from /usr/lib/mozilla/plugins/flash-mozilla.so
#2  0x0000000000b2a2c4 in WebKit::NetscapePlugin::initialize(WebKit::Plugin::Parameters const&) ()
#3  0x0000000000b015df in WebKit::PluginControllerProxy::initialize(WebKit::PluginCreationParameters const&) ()
#4  0x0000000000b0569f in WebKit::WebProcessConnection::createPluginInternal(WebKit::PluginCreationParameters const&, bool&, bool&, unsigned int&) ()

Only adobe can know why, though, but the thing is that it only crashes for windowed plugins, adding wmode=opaque as parameter or not calling NPP_GetValue and always loading the source URL, fixes the crash and the flash thing works perfectly. So, the only thing I can think of is adding a plugin quirk to handle this specific case.

[Carlos Garcia Campos]

Created attachment 239532 [details]
Patch

[Carlos Garcia Campos]

Committed r174507: <http://trac.webkit.org/changeset/174507>