From 56b50b945bccb66368088151924cd635782cdad1 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 5 Oct 2023 00:59:19 +0200 Subject: [PATCH] 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" Signed-off-by: Michael Niedermayer (cherry picked from commit ac4e3e188af8bf6f0c4a808a24f6ff0daba78248) Signed-off-by: Michael Niedermayer --- libavcodec/evc_parse.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/libavcodec/evc_parse.c b/libavcodec/evc_parse.c index 43b8dabf8b..cc9aa106fb 100644 --- a/libavcodec/evc_parse.c +++ b/libavcodec/evc_parse.c @@ -58,8 +58,12 @@ int ff_evc_parse_slice_header(GetBitContext *gb, EVCParserSliceHeader *sh, 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); }