From 9e67447a4ffacf28af8bace33faf3ea432ddc43e Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 16 Mar 2018 19:53:36 +0100 Subject: avformat/mov: Check STSC and remove invalid entries Fixes assertion failure Fixes: crbug 822547, crbug 822666 and crbug 823009 Affects: aark15sd_9A62E2FA.mp4 Found-by: ClusterFuzz Reviewed-by: Matt Wolenetz Signed-off-by: Michael Niedermayer --- libavformat/mov.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'libavformat/mov.c') diff --git a/libavformat/mov.c b/libavformat/mov.c index b7f9c0cdd1..33126781a0 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -2630,6 +2630,21 @@ static int mov_read_stsc(MOVContext *c, AVIOContext *pb, MOVAtom atom) } sc->stsc_count = i; + for (i = sc->stsc_count - 1; i < UINT_MAX; i--) { + if ((i+1 < sc->stsc_count && sc->stsc_data[i].first >= sc->stsc_data[i+1].first) || + (i > 0 && sc->stsc_data[i].first <= sc->stsc_data[i-1].first) || + sc->stsc_data[i].first < 1 || + sc->stsc_data[i].count < 1 || + sc->stsc_data[i].id < 1) { + av_log(c->fc, AV_LOG_WARNING, "STSC entry %d is invalid (first=%d count=%d id=%d)\n", i, sc->stsc_data[i].first, sc->stsc_data[i].count, sc->stsc_data[i].id); + if (i+1 >= sc->stsc_count || sc->stsc_data[i+1].first < 2) + return AVERROR_INVALIDDATA; + // We replace this entry by the next valid + sc->stsc_data[i].first = sc->stsc_data[i+1].first - 1; + sc->stsc_data[i].count = sc->stsc_data[i+1].count; + sc->stsc_data[i].id = sc->stsc_data[i+1].id; + } + } if (pb->eof_reached) { av_log(c->fc, AV_LOG_WARNING, "reached eof, corrupted STSC atom\n"); @@ -4119,6 +4134,11 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom) st->index); return 0; } + if (sc->stsc_count && sc->stsc_data[ sc->stsc_count - 1 ].first > sc->chunk_count) { + av_log(c->fc, AV_LOG_ERROR, "stream %d, contradictionary STSC and STCO\n", + st->index); + return AVERROR_INVALIDDATA; + } fix_timescale(c, sc); -- cgit v1.2.3