[FFmpeg-cvslog] shorten: fix "off by padding" bug

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Wed May 22 17:39:22 2013 +0200| [ad22767cb61cdc75541b21154d65fd1ad6351025] | committer: Michael Niedermayer

shorten: fix "off by padding" bug

Fixes array overread

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ad22767cb61cdc75541b21154d65fd1ad6351025
---

 libavcodec/shorten.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/shorten.c b/libavcodec/shorten.c
index 23c5d7c..3bba10c 100644
--- a/libavcodec/shorten.c
+++ b/libavcodec/shorten.c
@@ -437,7 +437,7 @@ static int shorten_decode_frame(AVCodecContext *avctx, void *data,
         buf_size       = FFMIN(buf_size, s->max_framesize - s->bitstream_size);
         input_buf_size = buf_size;
 
-        if (s->bitstream_index + s->bitstream_size + buf_size >
+        if (s->bitstream_index + s->bitstream_size + buf_size + FF_INPUT_BUFFER_PADDING_SIZE >
             s->allocated_bitstream_size) {
             memmove(s->bitstream, &s->bitstream[s->bitstream_index],
                     s->bitstream_size);