Gstreamer1-plugins-bad-free: gstreamer: denial of service via av1 tile_list_obu parser byte/bit confusion

A denial of service vulnerability was found in GStreamer's AV1 codec parser in gst-plugins-bad. The gst_av1_parser_parse_tile_list_obu() function passes a byte count to a bit-reader API that expects a bit count, causing parser desynchronization. A remote attacker could trick a user into opening a specially crafted AV1 media file, triggering an assertion abort and causing the application to crash.