From 12ec8ad24b07e3ad424b43813c1f84c7d336bdcd Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 1 Mar 2020 00:00:25 +0100 Subject: [PATCH] avcodec/siren: Check several indexes Fixes: Multiple out of array accesses Fixes: 20817/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SIREN_fuzzer-5754041227542528.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Paul B Mahol Signed-off-by: Michael Niedermayer --- libavcodec/siren.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/libavcodec/siren.c b/libavcodec/siren.c index 2577ff52dd..76dfe62843 100644 --- a/libavcodec/siren.c +++ b/libavcodec/siren.c @@ -428,6 +428,7 @@ static int decode_envelope(SirenContext *s, GetBitContext *gb, int *absolute_region_power_index, int esf_adjustment) { absolute_region_power_index[0] = (int)get_bits(gb, 5) - esf_adjustment; + absolute_region_power_index[0] = av_clip(absolute_region_power_index[0], -24, 39); decoder_standard_deviation[0] = s->standard_deviation[absolute_region_power_index[0] + 24]; for (int i = 1; i < number_of_regions; i++) { @@ -437,7 +438,7 @@ static int decode_envelope(SirenContext *s, GetBitContext *gb, index = differential_decoder_tree[i - 1][index][get_bits1(gb)]; } while (index > 0); - absolute_region_power_index[i] = absolute_region_power_index[i - 1] - index - 12; + absolute_region_power_index[i] = av_clip(absolute_region_power_index[i - 1] - index - 12, -24, 39); decoder_standard_deviation[i] = s->standard_deviation[absolute_region_power_index[i] + 24]; } @@ -500,6 +501,8 @@ static int categorize_regions(int number_of_regions, int number_of_available_bit } } } + if (raw_value == -99) + return AVERROR_INVALIDDATA; *min_rate_ptr++ = raw_min_idx; min += expected_bits_table[min_rate_categories[raw_min_idx] + 1] - @@ -518,6 +521,8 @@ static int categorize_regions(int number_of_regions, int number_of_available_bit } } } + if (raw_value == 99) + return AVERROR_INVALIDDATA; *--max_rate_ptr = raw_max_idx; max += expected_bits_table[max_rate_categories[raw_max_idx] - 1] - @@ -684,9 +689,11 @@ static int siren_decode(AVCodecContext *avctx, void *data, rate_control = get_bits(gb, 4); - categorize_regions(s->number_of_regions, get_bits_left(gb), - s->absolute_region_power_index, s->power_categories, - s->category_balance); + ret = categorize_regions(s->number_of_regions, get_bits_left(gb), + s->absolute_region_power_index, s->power_categories, + s->category_balance); + if (ret < 0) + return ret; for (int i = 0; i < rate_control; i++) s->power_categories[s->category_balance[i]]++;