[FFmpeg-cvslog] avcodec/pgssubdec: Check dimensions for 0

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Nov 14 18:06:37 2015 +0100| [ebf5264cd6bbda6c0c379dfeaaba3b9afc3279a8] | committer: Michael Niedermayer

avcodec/pgssubdec: Check dimensions for 0

Fixes division by 0
Fixes: b293a6479bb4b5286cff24d356bfd955/asan_generic_225c3c9_7819_cc526b657450c6cdef1371b526499626.mkv

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ebf5264cd6bbda6c0c379dfeaaba3b9afc3279a8
---

 libavcodec/pgssubdec.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
index a70c84b..61dc2ad 100644
--- a/libavcodec/pgssubdec.c
+++ b/libavcodec/pgssubdec.c
@@ -290,8 +290,8 @@ static int parse_object_segment(AVCodecContext *avctx,
     height = bytestream_get_be16(&buf);
 
     /* Make sure the bitmap is not too large */
-    if (avctx->width < width || avctx->height < height) {
-        av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions larger than video.\n");
+    if (avctx->width < width || avctx->height < height || !width || !height) {
+        av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions (%dx%d) invalid.\n", width, height);
         return AVERROR_INVALIDDATA;
     }