[FFmpeg-cvslog] avcodec/ptx: Check that the input contains at least one line

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Oct  2 22:05:52 2019 +0200| [a6ad328256fe6a6ace7d1e15f3515afccf1247fc] | committer: Michael Niedermayer

avcodec/ptx: Check that the input contains at least one line

Fixes: Timeout (19sec -> 44ms)
Fixes: 17816/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PTX_fuzzer-5704459950227456

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=a6ad328256fe6a6ace7d1e15f3515afccf1247fc
---

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

diff --git a/libavcodec/ptx.c b/libavcodec/ptx.c
index 42147f4afc..19f9305cda 100644
--- a/libavcodec/ptx.c
+++ b/libavcodec/ptx.c
@@ -55,6 +55,9 @@ static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 
     buf += offset;
 
+    if (buf_end - buf < w * bytes_per_pixel)
+        return AVERROR_INVALIDDATA;
+
     if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
         return ret;