[FFmpeg-cvslog] indeo5: check tile size in decode_mb_info().

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sun Apr 15 14:11:50 2012 +0200| [2d09cdbaf2f449ba23d54e97e94bd97ca22208c6] | committer: Anton Khirnov

indeo5: check tile size in decode_mb_info().

This prevents writing into a too small array if some parameters changed
without the tile being reallocated.

Fixes CVE-2012-2794

CC:libav-stable at libav.org

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2d09cdbaf2f449ba23d54e97e94bd97ca22208c6
---

 libavcodec/indeo5.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/indeo5.c b/libavcodec/indeo5.c
index 4f8e0d8..4044a04 100644
--- a/libavcodec/indeo5.c
+++ b/libavcodec/indeo5.c
@@ -430,6 +430,12 @@ static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band,
         ((band->qdelta_present && band->inherit_qdelta) || band->inherit_mv))
         return AVERROR_INVALIDDATA;
 
+    if (tile->num_MBs != IVI_MBs_PER_TILE(tile->width, tile->height, band->mb_size)) {
+        av_log(avctx, AV_LOG_ERROR, "Allocated tile size %d mismatches parameters %d\n",
+               tile->num_MBs, IVI_MBs_PER_TILE(tile->width, tile->height, band->mb_size));
+        return AVERROR_INVALIDDATA;
+    }
+
     /* scale factor for motion vectors */
     mv_scale = (ctx->planes[0].bands[0].mb_size >> 3) - (band->mb_size >> 3);
     mv_x = mv_y = 0;