[FFmpeg-cvslog] avcodec/cinepak: Check input packet size before frame reallocation

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Wed May 31 22:18:23 2017 +0200| [653de8249dab1a6c96bc4d5a049b3b9234c9a4ba] | committer: Michael Niedermayer

avcodec/cinepak: Check input packet size before frame reallocation

Reduces time spend decoding 1917/clusterfuzz-testcase-minimized-5023221273329664

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit e47057e932ff9a071d52fa1d5d4a956340eb2475)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=653de8249dab1a6c96bc4d5a049b3b9234c9a4ba
---

 libavcodec/cinepak.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libavcodec/cinepak.c b/libavcodec/cinepak.c
index 58c26dc69c..7a7466204a 100644
--- a/libavcodec/cinepak.c
+++ b/libavcodec/cinepak.c
@@ -322,9 +322,6 @@ static int cinepak_decode (CinepakContext *s)
     int           y0 = 0;
     int           encoded_buf_size;
 
-    if (s->size < 10)
-        return AVERROR_INVALIDDATA;
-
     frame_flags = s->data[0];
     num_strips  = AV_RB16 (&s->data[8]);
     encoded_buf_size = AV_RB24(&s->data[1]);
@@ -439,6 +436,9 @@ static int cinepak_decode_frame(AVCodecContext *avctx,
     s->data = buf;
     s->size = buf_size;
 
+    if (s->size < 10)
+        return AVERROR_INVALIDDATA;
+
     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
         return ret;