[FFmpeg-cvslog] xwddec: prevent overflow of lsize * avctx->height

[Andreas Cadhalpun]

ffmpeg | branch: release/2.8 | Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com> | Fri Dec 18 19:28:51 2015 +0100| [778c8de40f2c8d8bdbdf9a52306c59b6a425d401] | committer: Andreas Cadhalpun

xwddec: prevent overflow of lsize * avctx->height

This is used to check if the input buffer is large enough, so if this
overflows it can cause a false negative leading to a segmentation fault
in bytestream2_get_bufferu.

Reviewed-by: Michael Niedermayer <michael at niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
(cherry picked from commit 9d38f06d05efbb9d6196c27668eb943e934943ae)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=778c8de40f2c8d8bdbdf9a52306c59b6a425d401
---

 libavcodec/xwddec.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/xwddec.c b/libavcodec/xwddec.c
index 2febedc..64cd841 100644
--- a/libavcodec/xwddec.c
+++ b/libavcodec/xwddec.c
@@ -141,7 +141,7 @@ static int xwd_decode_frame(AVCodecContext *avctx, void *data,
         return AVERROR_INVALIDDATA;
     }
 
-    if (bytestream2_get_bytes_left(&gb) < ncolors * XWD_CMAP_SIZE + avctx->height * lsize) {
+    if (bytestream2_get_bytes_left(&gb) < ncolors * XWD_CMAP_SIZE + (uint64_t)avctx->height * lsize) {
         av_log(avctx, AV_LOG_ERROR, "input buffer too small\n");
         return AVERROR_INVALIDDATA;
     }