[FFmpeg-cvslog] indeo3: fix data size check

[Anton Khirnov]

ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Wed Apr 10 09:59:36 2013 +0200| [34e6af9e204ca6bb18d8cf8ec68fe19b0e083e95] | committer: Anton Khirnov

indeo3: fix data size check

The data offsets are relative to the bistream header, which is 16 bytes
after the start of the data.
Fixes invalid reads with corrupted files.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=34e6af9e204ca6bb18d8cf8ec68fe19b0e083e95
---

 libavcodec/indeo3.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libavcodec/indeo3.c b/libavcodec/indeo3.c
index 633bb30..004b618 100644
--- a/libavcodec/indeo3.c
+++ b/libavcodec/indeo3.c
@@ -893,8 +893,7 @@ static int decode_frame_headers(Indeo3DecodeContext *ctx, AVCodecContext *avctx,
 
     if (ctx->data_size == 16)
         return 4;
-    if (ctx->data_size > buf_size)
-        ctx->data_size = buf_size;
+    ctx->data_size = FFMIN(ctx->data_size, buf_size - 16);
 
     bytestream2_skip(&gb, 3); // skip reserved byte and checksum