Bug 164926 – [GTK] Memory corruption causes web process crash in WebCore::createStyleContext

• Status: NEW
• Component: WebKitGTK

[Michael Catanzaro]

Memory corruption causes web process crash in WebCore::createStyleContext. Only one report of this ever, with 2.12.4. Unfortunately I have no valgrind memcheck for this.

Truncated backtrace:
Thread no. 1 (10 frames)
 #6 g_malloc at gmem.c:94
 #7 g_data_set_internal at gdataset.c:464
 #8 g_datalist_id_set_data_full at gdataset.c:670
 #9 g_object_notify_queue_freeze at gobject.c:242
 #10 g_object_init at gobject.c:975
 #11 g_type_create_instance at gtype.c:1869
 #12 g_object_new_internal at gobject.c:1781
 #15 gtk_css_path_node_new at gtkcsspathnode.c:142
 #16 gtk_style_context_init at gtkstylecontext.c:355
 #17 g_type_create_instance at gtype.c:1875

Full backtrace downstream. Importantly:

#3  0x00007f904cc96c13 in malloc_printerr (ar_ptr=0x3, ptr=<optimized out>, str=0x7f904cda3250 "malloc(): smallbin double linked list corrupted", action=3) at malloc.c:5004
        buf = "000056427ea9ba30"
        cp = <optimized out>
        ar_ptr = 0x3
        ptr = <optimized out>
        str = 0x7f904cda3250 "malloc(): smallbin double linked list corrupted"
        action = 3

[Michael Catanzaro]

Note: last time we had a crash like this, it was an Epiphany bug in an unrelated part of code, due to forgetting to remove a weak pointer. Epiphany is not a likely culprit here since this is web process.