From acd49222eb03e10e8ac2191a508063d0e6f782df Mon Sep 17 00:00:00 2001 From: chcunningham Date: Thu, 13 Dec 2018 13:58:40 -0800 Subject: [PATCH] lavf/mov: ensure only one tkhd per trak Chromium fuzzing produced a whacky file with extra tkhds. This caused an AVStream that was already in use to be corrupted by assigning it a new id, which blows up later in mov_read_trun because the MOVFragmentStreamInfo.index_entry now points OOB. Reviewed-by: Baptiste Coudurier Signed-off-by: Michael Niedermayer (cherry picked from commit c9f7b6f7a9fdffa0ab8f3aa84a1f701cf5b3a6e9) Signed-off-by: Michael Niedermayer --- libavformat/mov.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index e48938e5b5..c5882be870 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -3019,7 +3019,7 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom) st = avformat_new_stream(c->fc, NULL); if (!st) return AVERROR(ENOMEM); - st->id = c->fc->nb_streams; + st->id = -1; sc = av_mallocz(sizeof(MOVStreamContext)); if (!sc) return AVERROR(ENOMEM); @@ -3265,6 +3265,11 @@ static int mov_read_tkhd(MOVContext *c, AVIOContext *pb, MOVAtom atom) st = c->fc->streams[c->fc->nb_streams-1]; sc = st->priv_data; + // Each stream (trak) should have exactly 1 tkhd. This catches bad files and + // avoids corrupting AVStreams mapped to an earlier tkhd. + if (st->id != -1) + return AVERROR_INVALIDDATA; + version = avio_r8(pb); flags = avio_rb24(pb); st->disposition |= (flags & MOV_TKHD_FLAG_ENABLED) ? AV_DISPOSITION_DEFAULT : 0;