[FFmpeg-cvslog] avcodec/movtextenc: Check for too long subtitles

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Tue Nov 30 09:21:35 2021 +0100| [f8e5e1c52333e6c330fbb4fe8ec2cb07240ca8c5] | committer: Andreas Rheinhardt

avcodec/movtextenc: Check for too long subtitles

Reviewed-by: Philip Langdale <philipl at overt.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f8e5e1c52333e6c330fbb4fe8ec2cb07240ca8c5
---

 libavcodec/movtextenc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c
index 46109e0a5e..eecadaf503 100644
--- a/libavcodec/movtextenc.c
+++ b/libavcodec/movtextenc.c
@@ -667,6 +667,8 @@ static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
         }
     }
 
+    if (s->byte_count > UINT16_MAX)
+        return AVERROR(ERANGE);
     AV_WB16(buf, s->byte_count);
     buf += 2;