[FFmpeg-cvslog] amrnbdec: check frame size before decoding.

[Vitor Sessak]

ffmpeg | branch: master | Vitor Sessak <vitor1001 at gmail.com> | Wed Feb 29 22:09:10 2012 +0100| [882abda5a26ffb8e3d1c5852dfa7cdad0a291d2d] | committer: Ronald S. Bultje

amrnbdec: check frame size before decoding.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable at libav.org
Signed-off-by: Ronald S. Bultje <rsbultje at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=882abda5a26ffb8e3d1c5852dfa7cdad0a291d2d
---

 libavcodec/amrnbdec.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/libavcodec/amrnbdec.c b/libavcodec/amrnbdec.c
index fff0e72..a7d0b4e 100644
--- a/libavcodec/amrnbdec.c
+++ b/libavcodec/amrnbdec.c
@@ -200,6 +200,10 @@ static enum Mode unpack_bitstream(AMRContext *p, const uint8_t *buf,
     p->bad_frame_indicator = !get_bits1(&gb); // quality bit
     skip_bits(&gb, 2);                        // two padding bits
 
+    if (mode >= N_MODES || buf_size < frame_sizes_nb[mode] + 1) {
+        return NO_DATA;
+    }
+
     if (mode < MODE_DTX)
         ff_amr_bit_reorder((uint16_t *) &p->frame, sizeof(AMRNBFrame), buf + 1,
                            amr_unpacking_bitmaps_per_mode[mode]);
@@ -947,6 +951,10 @@ static int amrnb_decode_frame(AVCodecContext *avctx, void *data,
     buf_out = (float *)p->avframe.data[0];
 
     p->cur_frame_mode = unpack_bitstream(p, buf, buf_size);
+    if (p->cur_frame_mode == NO_DATA) {
+        av_log(avctx, AV_LOG_ERROR, "Corrupt bitstream\n");
+        return AVERROR_INVALIDDATA;
+    }
     if (p->cur_frame_mode == MODE_DTX) {
         av_log_missing_feature(avctx, "dtx mode", 1);
         return -1;