(gdb) bt
#0  0x00007fff97c1db00 in tiny_free_list_add_ptr ()
#1  0x00007fff97c25825 in szone_free ()
#2  0x00007fff97c292d8 in szone_memalign ()
#3  0x00007fff97c5d15f in malloc_zone_memalign ()
#4  0x00007fff97c5deda in posix_memalign ()
#5  0x00000001005c1061 in av_mallocz (size=4310958080) at mem.c:94