[FFmpeg-cvslog] avcodec/bintext: Check input size before allocating the input image

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Sep 12 02:11:00 2018 +0200| [8db9097308dcc72f3f1f459a2b39f7a987ddd978] | committer: Michael Niedermayer

avcodec/bintext: Check input size before allocating the input image

Fixes: Timeout
Fixes: 9795/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_XBIN_fuzzer-5768631928487936

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=8db9097308dcc72f3f1f459a2b39f7a987ddd978
---

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

diff --git a/libavcodec/bintext.c b/libavcodec/bintext.c
index d967317671..b14a2a9c29 100644
--- a/libavcodec/bintext.c
+++ b/libavcodec/bintext.c
@@ -146,6 +146,9 @@ static int decode_frame(AVCodecContext *avctx,
     const uint8_t *buf_end = buf+buf_size;
     int ret;
 
+    if ((avctx->width / FONT_WIDTH) * (avctx->height / s->font_height) / 256 > buf_size)
+        return AVERROR_INVALIDDATA;
+
     s->x = s->y = 0;
     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
         return ret;