[FFmpeg-cvslog] wmavoice: limit wmavoice_decode_packet return value to packet size

[Andreas Cadhalpun]

ffmpeg | branch: release/2.7 | Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com> | Sun Jun 28 12:40:12 2015 +0200| [254fabe758a476587cefe96c49dbd8c8c3d575ac] | committer: Michael Niedermayer

wmavoice: limit wmavoice_decode_packet return value to packet size

Claiming to have decoded more bytes than the packet size is wrong.

Reviewed-by: Michael Niedermayer <michaelni at gmx.at>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
(cherry picked from commit 2a4700a4f03280fa8ba4fc0f8a9987bb550f0d1e)

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=254fabe758a476587cefe96c49dbd8c8c3d575ac
---

 libavcodec/wmavoice.c |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/libavcodec/wmavoice.c b/libavcodec/wmavoice.c
index ae88d4e..fff1aa8 100644
--- a/libavcodec/wmavoice.c
+++ b/libavcodec/wmavoice.c
@@ -1982,7 +1982,14 @@ static int wmavoice_decode_packet(AVCodecContext *ctx, void *data,
                     *got_frame_ptr) {
                     cnt += s->spillover_nbits;
                     s->skip_bits_next = cnt & 7;
-                    return cnt >> 3;
+                    res = cnt >> 3;
+                    if (res > avpkt->size) {
+                        av_log(ctx, AV_LOG_ERROR,
+                               "Trying to skip %d bytes in packet of size %d\n",
+                               res, avpkt->size);
+                        return AVERROR_INVALIDDATA;
+                    }
+                    return res;
                 } else
                     skip_bits_long (gb, s->spillover_nbits - cnt +
                                     get_bits_count(gb)); // resync
@@ -2001,7 +2008,14 @@ static int wmavoice_decode_packet(AVCodecContext *ctx, void *data,
     } else if (*got_frame_ptr) {
         int cnt = get_bits_count(gb);
         s->skip_bits_next = cnt & 7;
-        return cnt >> 3;
+        res = cnt >> 3;
+        if (res > avpkt->size) {
+            av_log(ctx, AV_LOG_ERROR,
+                   "Trying to skip %d bytes in packet of size %d\n",
+                   res, avpkt->size);
+            return AVERROR_INVALIDDATA;
+        }
+        return res;
     } else if ((s->sframe_cache_size = pos) > 0) {
         /* rewind bit reader to start of last (incomplete) superframe... */
         init_get_bits(gb, avpkt->data, size << 3);