avcodec/evc_parse: Check num_remaining_tiles_in_slice_minus1
Fixes: out of array access
Fixes: 62467/clusterfuzz-testcase-minimized-ffmpeg_BSF_EVC_FRAME_MERGE_fuzzer-6092990982258688
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: "Dawid Kozinski/Multimedia (PLT) /SRPOL/Staff Engineer/Samsung Electronics" <[email protected]>
Signed-off-by: Michael Niedermayer <[email protected]>
diff --git a/libavcodec/evc_parse.c b/libavcodec/evc_parse.c
index 43b8dab..cc9aa10 100644
--- a/libavcodec/evc_parse.c
+++ b/libavcodec/evc_parse.c
@@ -58,8 +58,12 @@
if (!sh->arbitrary_slice_flag)
sh->last_tile_id = get_bits(gb, pps->tile_id_len_minus1 + 1);
else {
- sh->num_remaining_tiles_in_slice_minus1 = get_ue_golomb_long(gb);
- num_tiles_in_slice = sh->num_remaining_tiles_in_slice_minus1 + 2;
+ unsigned num_remaining_tiles_in_slice_minus1 = get_ue_golomb_long(gb);
+ if (num_remaining_tiles_in_slice_minus1 > EVC_MAX_TILE_ROWS * EVC_MAX_TILE_COLUMNS - 2)
+ return AVERROR_INVALIDDATA;
+
+ num_tiles_in_slice = num_remaining_tiles_in_slice_minus1 + 2;
+ sh->num_remaining_tiles_in_slice_minus1 = num_remaining_tiles_in_slice_minus1;
for (int i = 0; i < num_tiles_in_slice - 1; ++i)
sh->delta_tile_id_minus1[i] = get_ue_golomb_long(gb);
}
