[FFmpeg-devel] [PATCH 2/6] avcodec/hevc_ps: Check num_ref_loc_offsets

[Michael Niedermayer]

Fixes: Writing arbitrarily over the array end
Fixes: 57812/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-4536557859373056

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/hevc_ps.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
index 348e4d8de2d..be1d668c263 100644
--- a/libavcodec/hevc_ps.c
+++ b/libavcodec/hevc_ps.c
@@ -1392,6 +1392,10 @@ static int pps_multilayer_extension(GetBitContext *gb, AVCodecContext *avctx,
         pps->pps_scaling_list_ref_layer_id = get_bits(gb, 6);
 
     pps->num_ref_loc_offsets = get_ue_golomb_long(gb);
+    if (pps->num_ref_loc_offsets > FF_ARRAY_ELEMS(pps->ref_loc_offset_layer_id)) {
+        pps->num_ref_loc_offsets = 0;
+        return AVERROR_INVALIDDATA;
+    }
     for (int i = 0; i < pps->num_ref_loc_offsets; i++) {
         pps->ref_loc_offset_layer_id[i] = get_bits(gb, 6);
         pps->scaled_ref_layer_offset_present_flag[i] = get_bits1(gb);
-- 
2.17.1