avcodec/hevc_ps: check scaling_list_dc_coef

Fixes: signed integer overflow: 2147483640 + 8 cannot be represented in type 'int'
Fixes: 28449/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-5686013259284480
Reviewed-by: James Almer <jamrial@gmail.com>
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
index ea6fd536c6b29c382f6bf83d866330cffa2128bf..139f3deeda8b9b0b74ee9421a04cc6c1fed23c90 100644 (file)
--- a/libavcodec/hevc_ps.c
+++ b/libavcodec/hevc_ps.c
@@ -816,7 +816,11 @@ static int scaling_list_data(GetBitContext *gb, AVCodecContext *avctx, ScalingLi
                 next_coef = 8;
                 coef_num  = FFMIN(64, 1 << (4 + (size_id << 1)));
                 if (size_id > 1) {
-                    scaling_list_dc_coef[size_id - 2][matrix_id] = get_se_golomb(gb) + 8;
+                    int scaling_list_coeff_minus8 = get_se_golomb(gb);
+                    if (scaling_list_coeff_minus8 < -7 ||
+                        scaling_list_coeff_minus8 > 247)
+                        return AVERROR_INVALIDDATA;
+                    scaling_list_dc_coef[size_id - 2][matrix_id] = scaling_list_coeff_minus8 + 8;
                     next_coef = scaling_list_dc_coef[size_id - 2][matrix_id];
                     sl->sl_dc[size_id - 2][matrix_id] = next_coef;
                 }