[FFmpeg-cvslog] avcodec/flacdec: Return error code instead of 0 for failures

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Tue May  9 13:25:34 2017 +0200| [224b47f76dbe360a394ef85b9a3beaf11bb39c5f] | committer: Michael Niedermayer

avcodec/flacdec: Return error code instead of 0 for failures

Fixes: infinite loop
Fixes: 1418/clusterfuzz-testcase-minimized-5934472438480896

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 3f5a68533decdfb4757207e8d7b5af06e1dcd197)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=224b47f76dbe360a394ef85b9a3beaf11bb39c5f
---

 libavcodec/flacdec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/flacdec.c b/libavcodec/flacdec.c
index f73a32b461..581c73efc8 100644
--- a/libavcodec/flacdec.c
+++ b/libavcodec/flacdec.c
@@ -205,12 +205,12 @@ static int get_metadata_size(const uint8_t *buf, int buf_size)
     buf += 4;
     do {
         if (buf_end - buf < 4)
-            return 0;
+            return AVERROR_INVALIDDATA;
         flac_parse_block_header(buf, &metadata_last, NULL, &metadata_size);
         buf += 4;
         if (buf_end - buf < metadata_size) {
             /* need more data in order to read the complete header */
-            return 0;
+            return AVERROR_INVALIDDATA;
         }
         buf += metadata_size;
     } while (!metadata_last);