[FFmpeg-cvslog] dcadec: check xch_base_channel against channel_order_tab.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Fri Dec 14 23:37:14 2012 +0100| [02d6d053396626ff5b3390e48a9933e0d4164b28] | committer: Michael Niedermayer

dcadec: check xch_base_channel against channel_order_tab.

Fix null pointer dereference

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=02d6d053396626ff5b3390e48a9933e0d4164b28
---

 libavcodec/dcadec.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/dcadec.c b/libavcodec/dcadec.c
index 59c1e6e..e7ae6e2 100644
--- a/libavcodec/dcadec.c
+++ b/libavcodec/dcadec.c
@@ -2247,6 +2247,8 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
                 } else {
                     s->channel_order_tab = dca_channel_reorder_nolfe_xch[s->amode];
                 }
+                if (s->channel_order_tab[s->xch_base_channel] < 0)
+                    return AVERROR_INVALIDDATA;
             } else {
                 channels = num_core_channels + !!s->lfe;
                 s->xch_present = 0; /* disable further xch processing */