[FFmpeg-cvslog] avcodec/pafvideo: Check input space for decode_0() before slow operations

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Apr 29 01:23:41 2019 +0200| [8d77debf7dab556b93ea9e936a7762b8e31420ac] | committer: Michael Niedermayer

avcodec/pafvideo: Check input space for decode_0() before slow operations

Fixes: Timeout (11sec -> 2sec)
Fixes: 14403/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PAF_VIDEO_fuzzer-5697465698746368

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8d77debf7dab556b93ea9e936a7762b8e31420ac
---

 libavcodec/pafvideo.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/pafvideo.c b/libavcodec/pafvideo.c
index 7c5861dfaf..7bfd6815df 100644
--- a/libavcodec/pafvideo.c
+++ b/libavcodec/pafvideo.c
@@ -285,6 +285,10 @@ static int paf_video_decode(AVCodecContext *avctx, void *data,
         return AVERROR_INVALIDDATA;
     }
 
+    if ((code & 0xF) == 0 &&
+        c->video_size / 32 - (int64_t)bytestream2_get_bytes_left(&c->gb) > c->video_size / 32 * (int64_t)avctx->discard_damaged_percentage / 100)
+        return AVERROR_INVALIDDATA;
+
     if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
         return ret;