#6618: flac: infinite loop with fuzzed file ----------------------------------+-------------------------------------- Reporter: jrummell | Type: defect Status: new | Priority: normal Component: avcodec | Version: git-master Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ----------------------------------+-------------------------------------- Summary of the bug: The attached file (generated by Chrome's fuzzers) causes an infinite loop. Original bug https://crbug.com/714370 How to reproduce: {{{ ffmpeg -i testcase.flac dummy.mp4 ffmpeg version N-87069-g1e34019d62 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3) configuration: ... libavutil 55. 74.100 / 55. 74.100 libavcodec 57.103.100 / 57.103.100 libavformat 57. 77.100 / 57. 77.100 libavdevice 57. 7.101 / 57. 7.101 libavfilter 6.100.100 / 6.100.100 libswscale 4. 7.103 / 4. 7.103 libswresample 2. 8.100 / 2. 8.100 libpostproc 54. 6.100 / 54. 6.100 [flac @ 0x3397360] Format flac detected only with low score of 13, misdetection possible! ... [NULL @ 0x2d998a0] crc check failed from offset 0 (frame 1) to 6 (frame 1) [NULL @ 0x2d998a0] sample/frame number mismatch in adjacent frames }}} In tracing through the code flac_parse() gets a buffer of 2 bytes, and ends up in handle_error:, returning 0. Code in parse_packet() detects that nothing is returned, and tries to parse the same 2 bytes again. -- Ticket URL: <https://trac.ffmpeg.org/ticket/6618> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker