[FFmpeg-cvslog] avformat/asfdec_o: Check size_bmp more fully

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Tue Jul  3 21:01:23 2018 +0200| [9dea41eac7229688e566a4a3e3f8251acf7ab97c] | committer: Michael Niedermayer

avformat/asfdec_o: Check size_bmp more fully

Fixes: integer overflow and out of array access
Fixes: asfo-crash-46080c4341572a7137a162331af77f6ded45cbd7

Found-by: Paul Ch <paulcher at icloud.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 2b46ebdbff1d8dec7a3d8ea280a612b91a582869)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9dea41eac7229688e566a4a3e3f8251acf7ab97c
---

 libavformat/asfdec_o.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c
index 5122e33c78..b4b2698368 100644
--- a/libavformat/asfdec_o.c
+++ b/libavformat/asfdec_o.c
@@ -706,7 +706,8 @@ static int parse_video_info(AVIOContext *pb, AVStream *st)
     st->codecpar->codec_id  = ff_codec_get_id(ff_codec_bmp_tags, tag);
     size_bmp = FFMAX(size_asf, size_bmp);
 
-    if (size_bmp > BMP_HEADER_SIZE) {
+    if (size_bmp > BMP_HEADER_SIZE &&
+        size_bmp < INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
         int ret;
         st->codecpar->extradata_size  = size_bmp - BMP_HEADER_SIZE;
         if (!(st->codecpar->extradata = av_malloc(st->codecpar->extradata_size +