[FFmpeg-cvslog] vcodec/agm: Alloc based on coded dimensions

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Nov 14 15:10:28 2019 +0100| [bfa8272f405314582e8f099ec1a9249232553c9c] | committer: Michael Niedermayer

vcodec/agm: Alloc based on coded dimensions

Fixes: out of array read
Fixes: 18715/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AGM_fuzzer-5659333417500672

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bfa8272f405314582e8f099ec1a9249232553c9c
---

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

diff --git a/libavcodec/agm.c b/libavcodec/agm.c
index 3b2c21e9a7..89f85f03c6 100644
--- a/libavcodec/agm.c
+++ b/libavcodec/agm.c
@@ -827,7 +827,7 @@ static int decode_intra(AVCodecContext *avctx, GetBitContext *gb, AVFrame *frame
 static int decode_motion_vectors(AVCodecContext *avctx, GetBitContext *gb)
 {
     AGMContext *s = avctx->priv_data;
-    int nb_mvs = ((avctx->height + 15) >> 4) * ((avctx->width + 15) >> 4);
+    int nb_mvs = ((avctx->coded_height + 15) >> 4) * ((avctx->coded_width + 15) >> 4);
     int ret, skip = 0, value, map;
 
     av_fast_padded_malloc(&s->mvectors, &s->mvectors_size,