[FFmpeg-devel] [PATCH 05/12] mov: validate time_scale

Andreas Cadhalpun andreas.cadhalpun at googlemail.com
Sun Oct 23 19:28:37 EEST 2016


A negative timescale doesn't make sense and triggers assertions in
av_rescale_rnd.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
---
 libavformat/mov.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 0a3fdd1..6f313a5 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1223,6 +1223,10 @@ static int mov_read_mdhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     mov_metadata_creation_time(&st->metadata, creation_time);
 
     sc->time_scale = avio_rb32(pb);
+    if (sc->time_scale <= 0) {
+        av_log(c->fc, AV_LOG_ERROR, "Invalid mdhd time scale %d\n", sc->time_scale);
+        return AVERROR_INVALIDDATA;
+    }
     st->duration = (version == 1) ? avio_rb64(pb) : avio_rb32(pb); /* duration */
 
     lang = avio_rb16(pb); /* language */
@@ -1248,7 +1252,10 @@ static int mov_read_mvhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     }
     mov_metadata_creation_time(&c->fc->metadata, creation_time);
     c->time_scale = avio_rb32(pb); /* time scale */
-
+    if (c->time_scale <= 0) {
+        av_log(c->fc, AV_LOG_ERROR, "Invalid mvhd time scale %d\n", c->time_scale);
+        return AVERROR_INVALIDDATA;
+    }
     av_log(c->fc, AV_LOG_TRACE, "time scale = %i\n", c->time_scale);
 
     c->duration = (version == 1) ? avio_rb64(pb) : avio_rb32(pb); /* duration */
-- 
2.9.3



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