[FFmpeg-cvslog] gifdec: check that the image dimensions are non-zero

[Anton Khirnov]

ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Fri Nov 15 10:15:24 2013 +0100| [c453723ad7d14abc5e82677eebaa6025fa598f08] | committer: Anton Khirnov

gifdec: check that the image dimensions are non-zero

Also add an error message an return a more suitable error code
(INVALIDDATA, not EINVAL);
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c453723ad7d14abc5e82677eebaa6025fa598f08
---

 libavcodec/gifdec.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c
index 136d112..b1207ae 100644
--- a/libavcodec/gifdec.c
+++ b/libavcodec/gifdec.c
@@ -87,8 +87,11 @@ static int gif_read_image(GifState *s, AVFrame *frame)
 
     /* verify that all the image is inside the screen dimensions */
     if (left + width > s->screen_width ||
-        top + height > s->screen_height)
-        return AVERROR(EINVAL);
+        top + height > s->screen_height ||
+        !width || !height) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid image dimensions.\n");
+        return AVERROR_INVALIDDATA;
+    }
 
     /* build the palette */
     n = (1 << bits_per_pixel);