[FFmpeg-devel] [PATCH] avcodec/h264_ps: Check offset_for_non_ref_pic and offset_for_top_to_bottom_field

[Michael Niedermayer]

Fixes: signed integer overflow: -2147483648 + -1 cannot be represented in type 'int'
Fixes: 14444/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_H264_fuzzer-5675880333967360

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/h264_ps.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libavcodec/h264_ps.c b/libavcodec/h264_ps.c
index 7c92c68b38..e38cf2a533 100644
--- a/libavcodec/h264_ps.c
+++ b/libavcodec/h264_ps.c
@@ -451,6 +451,15 @@ int ff_h264_decode_seq_parameter_set(GetBitContext *gb, AVCodecContext *avctx,
         sps->delta_pic_order_always_zero_flag = get_bits1(gb);
         sps->offset_for_non_ref_pic           = get_se_golomb_long(gb);
         sps->offset_for_top_to_bottom_field   = get_se_golomb_long(gb);
+
+        if (   sps->offset_for_non_ref_pic         == INT32_MIN
+            || sps->offset_for_top_to_bottom_field == INT32_MIN
+        ) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "offset_for_non_ref_pic or offset_for_top_to_bottom_field underflow\n");
+            goto fail;
+        }
+
         sps->poc_cycle_length                 = get_ue_golomb(gb);
 
         if ((unsigned)sps->poc_cycle_length >=
-- 
2.21.0