[FFmpeg-devel] [PATCH 1/2] avformat/mov: Break out early if chunk_count is 0 in mov_build_index()

Michael Niedermayer michael at niedermayer.cc
Tue May 15 18:06:59 EEST 2018


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 at niedermayer.cc>
---
 libavformat/mov.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 1975011741..4848a106f2 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3900,6 +3900,9 @@ 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;
-- 
2.17.0



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