Bug 264524

Summary: [GStreamer][MSE] Crash in _gst_element_request_pad
Product: WebKit Reporter: Michael Catanzaro <mcatanzaro>
Component: MediaAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: philn
Priority: P2    
Version: WebKit Nightly Build   
Hardware: PC   
OS: Linux   
Attachments:
Description Flags
Backtrace none

Description Michael Catanzaro 2023-11-09 15:06:07 PST 
Created attachment 468543 [details]
Backtrace

Using Epiphany Tech Preview with WebKitGTK 2.42.1 and GStreamer 1.22.5, my web process crashed when visiting https://apnews.com/article/donald-trump-letitia-james-fraud-trial-arthur-engoron-new-york-9b8ac3f485607b5aa95f35ab724efcd4

The crash is deep in GStreamer:

(gdb) bt
#0  g_type_check_instance_is_fundamentally_a
    (type_instance=type_instance@entry=0x7f1d640ad5c0, fundamental_type=fundamental_type@entry=0x50 [GObject])
    at ../gobject/gtype.c:4153
#1  0x00007f1ffb56583a in g_object_ref (_object=_object@entry=0x7f1d640ad5c0) at ../gobject/gobject.c:3715
#2  0x00007f1ffba6f2bf in gst_object_ref (object=0x7f1d640ad5c0) at ../gst/gstobject.c:240
#3  0x00007f1ffba99121 in _gst_element_request_pad
    (element=0x556f02df8820 [GstStreamSynchronizer|streamsynchronizer0], templ=0x556f02df7a90 [GstPadTemplate|sink_%u], name=<optimized out>, caps=caps@entry=0x0) at ../gst/gstelement.c:1182
#4  0x00007f1ffba992bf in gst_element_request_pad_simple
    (element=<optimized out>, name=name@entry=0x7f1f7a4a3668 "sink_%u") at ../gst/gstelement.c:1274
#5  0x00007f1f7a49c783 in gst_play_sink_do_reconfigure.isra.0
    (playsink=playsink@entry=0x556f02df8200 [GstPlaySink|playsink]) at ../gst/playback/gstplaysink.c:3623
#6  0x00007f1f7a48563e in sinkpad_blocked_cb
    (blockedpad=blockedpad@entry=0x556f02f562a0 [GstProxyPad|proxypad17], info=info@entry=0x7f1daf7fc7c0, user_data=0x556f02df8200) at ../gst/playback/gstplaysink.c:4450
#7  0x00007f1ffbac053f in probe_hook_marshal (hook=0x556f02ed5250, data=0x7f1daf7fc680) at ../gst/gstpad.c:3669
#8  0x00007f1ffad07f07 in g_hook_list_marshal
    (hook_list=hook_list@entry=0x556f02f56338, may_recurse=may_recurse@entry=1, marshaller=marshaller@entry=0x7f1ffbac0260 <probe_hook_marshal>, data=data@entry=0x7f1daf7fc680) at ../glib/ghook.c:674
#9  0x00007f1ffbac0bc8 in do_probe_callbacks
    (pad=pad@entry=0x556f02f562a0 [GstProxyPad|proxypad17], info=info@entry=0x7f1daf7fc7c0, defaultval=defaultval@entry=GST_FLOW_OK) at ../gst/gstpad.c:3853
#10 0x00007f1ffbac521a in gst_pad_push_event_unchecked
    (pad=pad@entry=0x556f02f562a0 [GstProxyPad|proxypad17], event=0x7f1d74003e10 [GstEvent], type=type@entry=GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM) at ../gst/gstpad.c:5521

I've attached a file containing a full backtrace of the crash thread, plus short backtraces of every thread.
Comment 1 Philippe Normand 2023-11-11 05:47:35 PST 
Here I get this:

(WebKitWebProcess:46): GStreamer-WARNING **: 05:47:05.580: ../gst/gstpad.c:5366:store_sticky_event:<avdec_h264-0:sink> Sticky event misordering, got 'caps' before 'stream-start'

Player spins, playback won't start. So yes, something wrong...