indeo5: check motion vectors.

fixes out of frame reading

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 10 insertions, 1 deletions

diff --git a/libavcodec/indeo5.c b/libavcodec/indeo5.c
index 2bacfa2885..52be725721 100644
--- a/libavcodec/indeo5.c
+++ b/libavcodec/indeo5.c
@@ -450,7 +450,7 @@ static int decode_mb_info(IVI5DecContext *ctx, IVIBandDesc *band,
                           IVITile *tile, AVCodecContext *avctx)
 {
     int         x, y, mv_x, mv_y, mv_delta, offs, mb_offset,
-                mv_scale, blks_per_mb;
+                mv_scale, blks_per_mb, s;
     IVIMbInfo   *mb, *ref_mb;
     int         row_offset = band->mb_size * band->pitch;
 
@@ -550,6 +550,15 @@ static int decode_mb_info(IVI5DecContext *ctx, IVIBandDesc *band,
                 }
             }
 
+            s= band->is_halfpel;
+            if (mb->type)
+            if ( x +  (mb->mv_x   >>s) +                 (y+               (mb->mv_y   >>s))*band->pitch < 0 ||
+                 x + ((mb->mv_x+s)>>s) + band->mb_size - 1
+                   + (y+band->mb_size - 1 +((mb->mv_y+s)>>s))*band->pitch > band->bufsize - 1) {
+                av_log(avctx, AV_LOG_ERROR, "motion vector %d %d outside reference\n", x*s + mb->mv_x, y*s + mb->mv_y);
+                return AVERROR_INVALIDDATA;
+            }
+
             mb++;
             if (ref_mb)
                 ref_mb++;