[FFmpeg-devel] [PATCH] NULL-check Matroska chapters when reading header

[Michael Niedermayer]

On Wed, Aug 06, 2014 at 08:29:40PM -0400, Justin Jacobs wrote:
> I have a Matroska file that contains a broken chapter (end time is before
> start time) that caused any ffmpeg-linked program to crash when accessing
> it. I've attached a patch that fixes the crash. Also, here is the backtrace
> of the crash for reference:
> 
> (gdb) backtrace
> #0  av_dict_set (pm=0x20, key=0x7ffff0bd14ef "title", value=0x7fffd80107e0
> "The End", flags=0) at libavutil/dict.c:71
> #1  0x00007ffff0b0e220 in matroska_read_header (s=0x20) at
> libavformat/matroskadec.c:2164
> #2  0x00007ffff0b9b233 in avformat_open_input (ps=0x7fffe00c1a08,
> filename=<optimized out>, fmt=<optimized out>, options=0x0) at
> libavformat/utils.c:599
> #3  0x00007ffff5fc9c32 in
> ffmpegthumbnailer::MovieDecoder::initialize(std::string const&) () from
> /usr/lib/libffmpegthumbnailer.so.4
> #4  0x00007ffff5fcd50f in
> ffmpegthumbnailer::VideoThumbnailer::generateThumbnail(std::string const&,
> ffmpegthumbnailer::ImageWriter&, AVFormatContext*) ()
>    from /usr/lib/libffmpegthumbnailer.so.4
> #5  0x00007ffff5fcd911 in
> ffmpegthumbnailer::VideoThumbnailer::generateThumbnail(std::string const&,
> ThumbnailerImageTypeEnum, std::string const&, AVFormatContext*) ()
>    from /usr/lib/libffmpegthumbnailer.so.4
> #6  0x00007ffff5fce636 in video_thumbnailer_generate_thumbnail_to_file ()
> from /usr/lib/libffmpegthumbnailer.so.4
> #7  0x00000000004314e5 in ?? ()
> #8  0x00000000004319a0 in ?? ()
> #9  0x000000000042221f in ?? ()
> #10 0x00000000004310bb in ?? ()
> #11 0x0000000000430dd0 in ?? ()
> #12 0x00007ffff644ec95 in ?? () from /usr/lib/libglib-2.0.so.0
> #13 0x00007ffff5766124 in start_thread () from /usr/lib/libpthread.so.0
> #14 0x00007ffff549a4bd in clone () from /usr/lib/libc.so.6
> 
> Thanks,
> Justin

>  matroskadec.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> b726d6b840582eee4f2503dc6c2d4a0a3a06ccfa  0001-NULL-check-Matroska-chapters-when-reading-header.patch
> From 14c4bcd96e6677c93b730faf0b4bf296e12bfd79 Mon Sep 17 00:00:00 2001
> From: Justin Jacobs <jajdorkster at gmail.com>
> Date: Wed, 6 Aug 2014 20:04:38 -0400
> Subject: [PATCH] NULL-check Matroska chapters when reading header

patch applied

note, iam still interrested in a testcase/file!

thanks

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

During times of universal deceit, telling the truth becomes a
revolutionary act. -- George Orwell
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