[FFmpeg-cvslog] avcodec/wmaprodec: Check offset

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Nov 12 20:06:35 2019 +0100| [5473c7825ea627a115155313a56a907d67a0d0c1] | committer: Michael Niedermayer

avcodec/wmaprodec: Check offset

Fixes: index 33280 out of bounds for type 'float [32768]'
Fixes: 18718/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_XMA2_fuzzer-5635373899710464

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5473c7825ea627a115155313a56a907d67a0d0c1
---

 libavcodec/wmaprodec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
index 6a22e2f552..775f17381f 100644
--- a/libavcodec/wmaprodec.c
+++ b/libavcodec/wmaprodec.c
@@ -1803,6 +1803,11 @@ static int xma_decode_packet(AVCodecContext *avctx, void *data,
     ret = decode_packet(avctx, &s->xma[s->current_stream], s->frames[s->current_stream],
                         &got_stream_frame_ptr, avpkt);
 
+    if (got_stream_frame_ptr && s->offset[s->current_stream] >= 64) {
+        got_stream_frame_ptr = 0;
+        ret = AVERROR_INVALIDDATA;
+    }
+
     /* copy stream samples (1/2ch) to sample buffer (Nch) */
     if (got_stream_frame_ptr) {
         int start_ch = s->start_channel[s->current_stream];