From bf77e5c752053652c6ef0036d1cc68999df40125 Mon Sep 17 00:00:00 2001 From: Pierre-Anthony Lemieux Date: Thu, 10 Aug 2023 16:40:13 -0700 Subject: [PATCH] avcodec/jpeg2000: check if decoding will exceed internal precision --- libavcodec/jpeg2000htdec.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/libavcodec/jpeg2000htdec.c b/libavcodec/jpeg2000htdec.c index 2c4cea5dd9..713dba17e3 100644 --- a/libavcodec/jpeg2000htdec.c +++ b/libavcodec/jpeg2000htdec.c @@ -572,6 +572,14 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s, const uint8_t *vlc_buf = Dcup + Pcup; + /* + * Bound on the recision needed to process the codeblock. The number of + * decoded bit planes is equal to at most cblk->zbp + 2 since S_blk = P if + * there are no placeholder passes or HT Sets and P = cblk->zbp. See Rec. + * ITU-T T.814, 7.6. + */ + int maxbp = cblk->zbp + 2; + /* convert to raster-scan */ const uint16_t is_border_x = width % 2; const uint16_t is_border_y = height % 2; @@ -590,6 +598,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s, goto free; } + /* do we have enough precision, assuming a 32-bit decoding path */ + if (maxbp >= 32) + return AVERROR_INVALIDDATA; + sigma = sigma_n; mu = mu_n; @@ -676,6 +688,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s, } U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1]; U[J2K_Q2] = kappa[J2K_Q2] + u[J2K_Q2]; + if (U[J2K_Q1] > maxbp || U[J2K_Q2] > maxbp) { + ret = AVERROR_INVALIDDATA; + goto free; + } for (int i = 0; i < 4; i++) { m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1); @@ -713,6 +729,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s, } U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1]; + if (U[J2K_Q1] > maxbp) { + ret = AVERROR_INVALIDDATA; + goto free; + } for (int i = 0; i < 4; i++) m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1); @@ -842,6 +862,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s, U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1]; U[J2K_Q2] = kappa[J2K_Q2] + u[J2K_Q2]; + if (U[J2K_Q1] > maxbp || U[J2K_Q2] > maxbp) { + ret = AVERROR_INVALIDDATA; + goto free; + } for (int i = 0; i < 4; i++) { m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1); @@ -910,6 +934,10 @@ static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s, kappa[J2K_Q1] = FFMAX(1, gamma[J2K_Q1] * (max_e[J2K_Q1] - 1)); U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1]; + if (U[J2K_Q1] > maxbp) { + ret = AVERROR_INVALIDDATA; + goto free; + } for (int i = 0; i < 4; i++) m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1); @@ -1238,8 +1266,10 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c } if ((ret = jpeg2000_decode_ht_cleanup_segment(s, cblk, t1, &mel_state, &mel, &vlc, &mag_sgn, Dcup, Lcup, Pcup, pLSB, width, - height, sample_buf, block_states)) < 0) + height, sample_buf, block_states)) < 0) { + av_log(s->avctx, AV_LOG_ERROR, "Bad HT cleanup segment\n"); goto free; + } if (cblk->npasses > 1) jpeg2000_decode_sigprop_segment(cblk, width, height, Dref, Lref,