[FFmpeg-cvslog] avcodec/cinepak: Check available input against encoded buffer size

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun May 12 22:06:30 2019 +0200| [87a54e150e9cb6479e590faaf66d9f405a97fb6c] | committer: Michael Niedermayer

avcodec/cinepak: Check available input against encoded buffer size

Fixes: Timeout (12sec -> 2sec)
Fixes: 14606/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CINEPAK_fuzzer-5738687561728000

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Tomas Härdin <tjoppen at acc.umu.se>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=87a54e150e9cb6479e590faaf66d9f405a97fb6c
---

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

diff --git a/libavcodec/cinepak.c b/libavcodec/cinepak.c
index a5132ddbc0..aeb15de0ed 100644
--- a/libavcodec/cinepak.c
+++ b/libavcodec/cinepak.c
@@ -323,6 +323,9 @@ static int cinepak_predecode_check (CinepakContext *s)
     num_strips  = AV_RB16 (&s->data[8]);
     encoded_buf_size = AV_RB24(&s->data[1]);
 
+    if (s->size < encoded_buf_size * (int64_t)(100 - s->avctx->discard_damaged_percentage) / 100)
+        return AVERROR_INVALIDDATA;
+
     /* if this is the first frame, check for deviant Sega FILM data */
     if (s->sega_film_skip_bytes == -1) {
         if (!encoded_buf_size) {