[FFmpeg-cvslog] avcodec/h264_parse: Check picture structure when initializing weight table

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Jun 10 00:13:07 2017 +0200| [09096fb68713089a8f97c8fa24e9d7f3bb9231d5] | committer: Michael Niedermayer

avcodec/h264_parse: Check picture structure when initializing weight table

Fixes: runtime error: index 49 out of bounds for type 'int [48][2][2]'
Fixes: 2159/clusterfuzz-testcase-minimized-5267945972301824

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=09096fb68713089a8f97c8fa24e9d7f3bb9231d5
---

 libavcodec/h264_parse.c  | 15 +++++++++------
 libavcodec/h264_parse.h  |  3 ++-
 libavcodec/h264_parser.c |  2 +-
 libavcodec/h264_slice.c  |  3 ++-
 4 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/libavcodec/h264_parse.c b/libavcodec/h264_parse.c
index ea202e759c..3d20075f6a 100644
--- a/libavcodec/h264_parse.c
+++ b/libavcodec/h264_parse.c
@@ -26,7 +26,8 @@
 
 int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
                               const int *ref_count, int slice_type_nos,
-                              H264PredWeightTable *pwt, void *logctx)
+                              H264PredWeightTable *pwt,
+                              int picture_structure, void *logctx)
 {
     int list, i, j;
     int luma_def, chroma_def;
@@ -98,11 +99,13 @@ int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
             }
 
             // for MBAFF
-            pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
-            pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];
-            for (j = 0; j < 2; j++) {
-                pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0];
-                pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1];
+            if (picture_structure == PICT_FRAME) {
+                pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
+                pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];
+                for (j = 0; j < 2; j++) {
+                    pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0];
+                    pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1];
+                }
             }
         }
         if (slice_type_nos != AV_PICTURE_TYPE_B)
diff --git a/libavcodec/h264_parse.h b/libavcodec/h264_parse.h
index 290da34d44..4d01620125 100644
--- a/libavcodec/h264_parse.h
+++ b/libavcodec/h264_parse.h
@@ -55,7 +55,8 @@ typedef struct H264POCContext {
 
 int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
                               const int *ref_count, int slice_type_nos,
-                              H264PredWeightTable *pwt, void *logctx);
+                              H264PredWeightTable *pwt,
+                              int picture_structure, void *logctx);
 
 /**
  * Check if the top & left blocks are available if needed & change the
diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c
index bc35a6146e..2564c6c6c3 100644
--- a/libavcodec/h264_parser.c
+++ b/libavcodec/h264_parser.c
@@ -202,7 +202,7 @@ static int scan_mmco_reset(AVCodecParserContext *s, GetBitContext *gb,
     if ((p->ps.pps->weighted_pred && slice_type_nos == AV_PICTURE_TYPE_P) ||
         (p->ps.pps->weighted_bipred_idc == 1 && slice_type_nos == AV_PICTURE_TYPE_B))
         ff_h264_pred_weight_table(gb, p->ps.sps, ref_count, slice_type_nos,
-                                  &pwt, logctx);
+                                  &pwt, p->picture_structure, logctx);
 
     if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
         int i;
diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 8ba23712a1..23ca32a39d 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1801,7 +1801,8 @@ static int h264_slice_header_parse(const H264Context *h, H264SliceContext *sl,
         (pps->weighted_bipred_idc == 1 &&
          sl->slice_type_nos == AV_PICTURE_TYPE_B)) {
         ret = ff_h264_pred_weight_table(&sl->gb, sps, sl->ref_count,
-                                  sl->slice_type_nos, &sl->pwt, h->avctx);
+                                  sl->slice_type_nos, &sl->pwt,
+                                  picture_structure, h->avctx);
         if (ret < 0)
             return ret;
     }