[FFmpeg-cvslog] mjpeg: Validate sampling factors

[Luca Barbato]

ffmpeg | branch: release/1.1 | Luca Barbato <lu_zero at gentoo.org> | Mon May 13 19:32:04 2013 +0200| [7923a25fdda9482107a94ade1e8e855f863e03b8] | committer: Reinhard Tartler

mjpeg: Validate sampling factors

They must be non-zero.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable at libav.org
(cherry picked from commit 8aa3500905fec6c4e657bb291b861d43c34d3de9)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7923a25fdda9482107a94ade1e8e855f863e03b8
---

 libavcodec/mjpegdec.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 5b59e48..9551850 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -265,6 +265,13 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
         s->quant_index[i] = get_bits(&s->gb, 8);
         if (s->quant_index[i] >= 4)
             return AVERROR_INVALIDDATA;
+        if (!s->h_count[i] || !s->v_count[i]) {
+            av_log(s->avctx, AV_LOG_ERROR,
+                   "Invalid sampling factor in component %d %d:%d\n",
+                   i, s->h_count[i], s->v_count[i]);
+            return AVERROR_INVALIDDATA;
+        }
+
         av_log(s->avctx, AV_LOG_DEBUG, "component %d %d:%d id: %d quant:%d\n",
                i, s->h_count[i], s->v_count[i],
                s->component_id[i], s->quant_index[i]);