avformat/mov: Break out early if chunk_count is 0 in mov_build_index()
authorMichael Niedermayer <michael@niedermayer.cc>
Tue, 15 May 2018 15:06:59 +0000 (17:06 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Mon, 16 Jul 2018 17:06:27 +0000 (19:06 +0200)
Without this some operations might overflow (undefined behavior)
even though the index adding loop would never execute

No testcase known

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 56e76bd0579cc7f7b28860885d9e569a39daf41b)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavformat/mov.c

index 1152634..c4d3863 100644 (file)
@@ -3516,6 +3516,9 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
     } else {
         unsigned chunk_samples, total = 0;
 
+        if (!sc->chunk_count)
+            return;
+
         // compute total chunk count
         for (i = 0; i < sc->stsc_count; i++) {
             unsigned count, chunk_count;