ffmpeg | branch: release/3.0 | Michael Niedermayer <michael@niedermayer.cc> | Wed Sep 28 16:14:08 2016 +0200| [8c43f320574d201fe1b696b133c08368f5f18508] | committer: Michael Niedermayer avformat/avidec: Check nb_streams in read_gab2_sub() Fixes null pointer dereference Fixes: 1/null_point.avi Found-by: 连一汉 <lianyihan@360.cn> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> (cherry picked from commit 2679ad4773aa356e7c3da5c68bc81f02a194617f) Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8c43f320574d201fe1...

libavformat/avidec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libavformat/avidec.c b/libavformat/avidec.c index 2e053a3..7adb819 100644 --- a/libavformat/avidec.c +++ b/libavformat/avidec.c @@ -1094,6 +1094,8 @@ static int read_gab2_sub(AVFormatContext *s, AVStream *st, AVPacket *pkt) goto error; if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) { + if (ast->sub_ctx->nb_streams != 1) + goto error; ff_read_packet(ast->sub_ctx, &ast->sub_pkt); *st->codec = *ast->sub_ctx->streams[0]->codec; ast->sub_ctx->streams[0]->codec->extradata = NULL;