From: Vittorio Giovara <vittorio.giovara@gmail.com>
Date: Wed, 13 Jul 2016 19:02:41 +0000 (-0400)
Subject: mov: Rework the check for invalid indexes in stsc
X-Git-Tag: n3.4-dev~10^2~498
X-Git-Url: http://git.ffmpeg.org/gitweb/ffmpeg.git/commitdiff_plain/ed9b2a5178d7a7c5a95694da3a808af327f36aff

mov: Rework the check for invalid indexes in stsc

There are samples with invalid stsc that may work fine as is and
do not need extradata change. So ignore any out of range index, and
error out only when explode is set.

Found-by: Matthieu Bouron <matthieu.bouron@stupeflix.com>

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
---

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 826be02..ff39b58 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1949,8 +1949,13 @@ static int mov_read_stsc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         sc->stsc_data[i].first = avio_rb32(pb);
         sc->stsc_data[i].count = avio_rb32(pb);
         sc->stsc_data[i].id = avio_rb32(pb);
-        if (sc->stsc_data[i].id > sc->stsd_count)
-            return AVERROR_INVALIDDATA;
+        if (sc->stsc_data[i].id < 0 || sc->stsc_data[i].id > sc->stsd_count) {
+            sc->stsc_data[i].id = 0;
+            if (c->fc->error_recognition & AV_EF_EXPLODE) {
+                av_log(c->fc, AV_LOG_ERROR, "Invalid stsc index.\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
     }
 
     sc->stsc_count = i;