From 7274d849cc44f9e4c5573d1b271d99f46ad7d583 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 14 Sep 2018 00:22:13 +0200 Subject: [PATCH] avcodec/diracdec: Propagate errors from codeblock() Consider a component to be damaged if more than 50% of its subbands are damaged Fixes: Timeout (part 1 of 2) Fixes: 9774/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5748957085958144 Signed-off-by: Michael Niedermayer --- libavcodec/diracdec.c | 47 +++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 15 deletions(-) diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c index 9a417caec5..cbd7fd1532 100644 --- a/libavcodec/diracdec.c +++ b/libavcodec/diracdec.c @@ -488,7 +488,7 @@ UNPACK_ARITH(10, int32_t) * Decode the coeffs in the rectangle defined by left, right, top, bottom * [DIRAC_STD] 13.4.3.2 Codeblock unpacking loop. codeblock() */ -static inline void codeblock(DiracContext *s, SubBand *b, +static inline int codeblock(DiracContext *s, SubBand *b, GetBitContext *gb, DiracArith *c, int left, int right, int top, int bottom, int blockcnt_one, int is_arith) @@ -505,7 +505,7 @@ static inline void codeblock(DiracContext *s, SubBand *b, zero_block = get_bits1(gb); if (zero_block) - return; + return 0; } if (s->codeblock_mode && !(s->old_delta_quant && blockcnt_one)) { @@ -516,7 +516,7 @@ static inline void codeblock(DiracContext *s, SubBand *b, quant = dirac_get_se_golomb(gb); if (quant > INT_MAX - b->quant || b->quant + quant < 0) { av_log(s->avctx, AV_LOG_ERROR, "Invalid quant\n"); - return; + return AVERROR_INVALIDDATA; } b->quant += quant; } @@ -524,7 +524,7 @@ static inline void codeblock(DiracContext *s, SubBand *b, if (b->quant > (DIRAC_MAX_QUANT_INDEX - 1)) { av_log(s->avctx, AV_LOG_ERROR, "Unsupported quant %d\n", b->quant); b->quant = 0; - return; + return AVERROR_INVALIDDATA; } qfactor = ff_dirac_qscale_tab[b->quant]; @@ -559,6 +559,7 @@ static inline void codeblock(DiracContext *s, SubBand *b, buf += b->stride; } } + return 0; } /** @@ -593,7 +594,7 @@ INTRA_DC_PRED(10, uint32_t) * Dirac Specification -> * 13.4.2 Non-skipped subbands. subband_coeffs() */ -static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b, int is_arith) +static av_always_inline int decode_subband_internal(DiracContext *s, SubBand *b, int is_arith) { int cb_x, cb_y, left, right, top, bottom; DiracArith c; @@ -601,9 +602,10 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b int cb_width = s->codeblock[b->level + (b->orientation != subband_ll)].width; int cb_height = s->codeblock[b->level + (b->orientation != subband_ll)].height; int blockcnt_one = (cb_width + cb_height) == 2; + int ret; if (!b->length) - return; + return 0; init_get_bits8(&gb, b->coeff_data, b->length); @@ -616,7 +618,9 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b left = 0; for (cb_x = 0; cb_x < cb_width; cb_x++) { right = (b->width * (cb_x+1LL)) / cb_width; - codeblock(s, b, &gb, &c, left, right, top, bottom, blockcnt_one, is_arith); + ret = codeblock(s, b, &gb, &c, left, right, top, bottom, blockcnt_one, is_arith); + if (ret < 0) + return ret; left = right; } top = bottom; @@ -629,33 +633,35 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b intra_dc_prediction_8(b); } } + return 0; } static int decode_subband_arith(AVCodecContext *avctx, void *b) { DiracContext *s = avctx->priv_data; - decode_subband_internal(s, b, 1); - return 0; + return decode_subband_internal(s, b, 1); } static int decode_subband_golomb(AVCodecContext *avctx, void *arg) { DiracContext *s = avctx->priv_data; SubBand **b = arg; - decode_subband_internal(s, *b, 0); - return 0; + return decode_subband_internal(s, *b, 0); } /** * Dirac Specification -> * [DIRAC_STD] 13.4.1 core_transform_data() */ -static void decode_component(DiracContext *s, int comp) +static int decode_component(DiracContext *s, int comp) { AVCodecContext *avctx = s->avctx; SubBand *bands[3*MAX_DWT_LEVELS+1]; enum dirac_subband orientation; int level, num_bands = 0; + int ret[3*MAX_DWT_LEVELS+1]; + int i; + int damaged_count = 0; /* Unpack all subbands at all levels. */ for (level = 0; level < s->wavelet_depth; level++) { @@ -677,11 +683,20 @@ static void decode_component(DiracContext *s, int comp) /* arithmetic coding has inter-level dependencies, so we can only execute one level at a time */ if (s->is_arith) avctx->execute(avctx, decode_subband_arith, &s->plane[comp].band[level][!!level], - NULL, 4-!!level, sizeof(SubBand)); + ret + 3*level + !!level, 4-!!level, sizeof(SubBand)); } /* golomb coding has no inter-level dependencies, so we can execute all subbands in parallel */ if (!s->is_arith) - avctx->execute(avctx, decode_subband_golomb, bands, NULL, num_bands, sizeof(SubBand*)); + avctx->execute(avctx, decode_subband_golomb, bands, ret, num_bands, sizeof(SubBand*)); + + for (i = 0; i < s->wavelet_depth * 3 + 1; i++) { + if (ret[i] < 0) + damaged_count++; + } + if (damaged_count > (s->wavelet_depth * 3 + 1) /2) + return AVERROR_INVALIDDATA; + + return 0; } #define PARSE_VALUES(type, x, gb, ebits, buf1, buf2) \ @@ -1867,7 +1882,9 @@ static int dirac_decode_frame_internal(DiracContext *s) if (!s->zero_res && !s->low_delay) { memset(p->idwt.buf, 0, p->idwt.stride * p->idwt.height); - decode_component(s, comp); /* [DIRAC_STD] 13.4.1 core_transform_data() */ + ret = decode_component(s, comp); /* [DIRAC_STD] 13.4.1 core_transform_data() */ + if (ret < 0) + return ret; } ret = ff_spatial_idwt_init(&d, &p->idwt, s->wavelet_idx+2, s->wavelet_depth, s->bit_depth);