From a7f03fc523db2f305ffd73220b12fb5a6bd2b3b6 Mon Sep 17 00:00:00 2001 From: "A. Wilcox" Date: Thu, 17 Sep 2020 06:07:33 +0000 Subject: user/libmad: Fix CVE-2018-7263 (closes #122) --- user/libmad/APKBUILD | 8 +- user/libmad/CVE-2018-7263.patch | 817 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 824 insertions(+), 1 deletion(-) create mode 100644 user/libmad/CVE-2018-7263.patch (limited to 'user/libmad') diff --git a/user/libmad/APKBUILD b/user/libmad/APKBUILD index 38f6a0deb..358496da1 100644 --- a/user/libmad/APKBUILD +++ b/user/libmad/APKBUILD @@ -2,7 +2,7 @@ # Maintainer: pkgname=libmad pkgver=0.15.1b -pkgrel=9 +pkgrel=1 pkgdesc="A high-quality MPEG audio decoder" url="https://www.underbit.com/products/mad/" arch="all" @@ -15,10 +15,15 @@ source="https://downloads.sourceforge.net/sourceforge/mad/$pkgname-$pkgver.tar.g libmad-0.15.1b-cflags-O2.patch libmad-0.15.1b-cflags.patch automake.patch + CVE-2018-7263.patch Provide-Thumb-2-alternative-code-for-MAD_F_MLN.patch mad.pc " +# secfixes: +# 0.15.1b-r1: +# - CVE-2018-7263 + prepare() { update_config_sub default_prepare @@ -45,5 +50,6 @@ sha512sums="2cad30347fb310dc605c46bacd9da117f447a5cabedd8fefdb24ab5de641429e5ec5 13a8bac30cea4861f903b4abc8673f9a35b6253aae6a02915f99b67e5e8c56460fc1fb059a0aa52143b665f888928baba098daf0ed022420e46317be4dbc6161 libmad-0.15.1b-cflags-O2.patch 01dc8421dba2b652aa8ca6d1f1a5c310645465b18190ebfdeaae516de881869957e8e7c0c373d0d09623da33719d01e028f2f6164790b54c43a71271f5b4dbba libmad-0.15.1b-cflags.patch e73ec5ae3b14e8d45579b52bcc561a309b85e1e51d946e061e2f0a9252f515e48e2d818e8bdce1adf5a9801ec314be8c911914d0bb12f9113a7afc54cf385250 automake.patch +dd412962246d4c9db8c07dbafcaba2f64fdc0c94cf6bcc3f4f0f88a92800f40e550cc56dc8a2324c0123d9c70a89055dc50cd714206d7886e2f6877d4cc26600 CVE-2018-7263.patch 9e9af20050c922c1c2f0b55009ae0eb20c9381eaff071f0dfee8a7b3a357e58f835f69364beb99820f5672459d88ac483d2419e1f9532d763779aafad7cbf72b Provide-Thumb-2-alternative-code-for-MAD_F_MLN.patch ec0b14bd0c6236a216107b507b92c06e295352f1657ba5e45f37fff220a73e1454b262ac36fc715d698c4ffd210d348fca71cf0198e2c49d16fe0ec5ea839f08 mad.pc" diff --git a/user/libmad/CVE-2018-7263.patch b/user/libmad/CVE-2018-7263.patch new file mode 100644 index 000000000..80e48469e --- /dev/null +++ b/user/libmad/CVE-2018-7263.patch @@ -0,0 +1,817 @@ +From: Kurt Roeckx +Date: Sun, 28 Jan 2018 19:26:36 +0100 +Subject: Check the size before reading with mad_bit_read + +There are various cases where it attemps to read past the end of the buffer +using mad_bit_read(). Most functions didn't even know the size of the buffer +they were reading from. + +Index: libmad-0.15.1b/bit.c +=================================================================== +--- libmad-0.15.1b.orig/bit.c ++++ libmad-0.15.1b/bit.c +@@ -138,6 +138,9 @@ unsigned long mad_bit_read(struct mad_bi + { + register unsigned long value; + ++ if (len == 0) ++ return 0; ++ + if (bitptr->left == CHAR_BIT) + bitptr->cache = *bitptr->byte; + +Index: libmad-0.15.1b/frame.c +=================================================================== +--- libmad-0.15.1b.orig/frame.c ++++ libmad-0.15.1b/frame.c +@@ -120,11 +120,18 @@ static + int decode_header(struct mad_header *header, struct mad_stream *stream) + { + unsigned int index; ++ struct mad_bitptr bufend_ptr; + + header->flags = 0; + header->private_bits = 0; + ++ mad_bit_init(&bufend_ptr, stream->bufend); ++ + /* header() */ ++ if (mad_bit_length(&stream->ptr, &bufend_ptr) < 32) { ++ stream->error = MAD_ERROR_BUFLEN; ++ return -1; ++ } + + /* syncword */ + mad_bit_skip(&stream->ptr, 11); +@@ -225,8 +232,13 @@ int decode_header(struct mad_header *hea + /* error_check() */ + + /* crc_check */ +- if (header->flags & MAD_FLAG_PROTECTION) ++ if (header->flags & MAD_FLAG_PROTECTION) { ++ if (mad_bit_length(&stream->ptr, &bufend_ptr) < 16) { ++ stream->error = MAD_ERROR_BUFLEN; ++ return -1; ++ } + header->crc_target = mad_bit_read(&stream->ptr, 16); ++ } + + return 0; + } +@@ -338,7 +350,7 @@ int mad_header_decode(struct mad_header + stream->error = MAD_ERROR_BUFLEN; + goto fail; + } +- else if (!(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) { ++ else if ((end - ptr >= 2) && !(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) { + /* mark point where frame sync word was expected */ + stream->this_frame = ptr; + stream->next_frame = ptr + 1; +@@ -361,6 +373,8 @@ int mad_header_decode(struct mad_header + ptr = mad_bit_nextbyte(&stream->ptr); + } + ++ stream->error = MAD_ERROR_NONE; ++ + /* begin processing */ + stream->this_frame = ptr; + stream->next_frame = ptr + 1; /* possibly bogus sync word */ +@@ -413,7 +427,7 @@ int mad_header_decode(struct mad_header + /* check that a valid frame header follows this frame */ + + ptr = stream->next_frame; +- if (!(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) { ++ if ((end - ptr >= 2) && !(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) { + ptr = stream->next_frame = stream->this_frame + 1; + goto sync; + } +Index: libmad-0.15.1b/layer12.c +=================================================================== +--- libmad-0.15.1b.orig/layer12.c ++++ libmad-0.15.1b/layer12.c +@@ -72,10 +72,18 @@ mad_fixed_t const linear_table[14] = { + * DESCRIPTION: decode one requantized Layer I sample from a bitstream + */ + static +-mad_fixed_t I_sample(struct mad_bitptr *ptr, unsigned int nb) ++mad_fixed_t I_sample(struct mad_bitptr *ptr, unsigned int nb, struct mad_stream *stream) + { + mad_fixed_t sample; ++ struct mad_bitptr frameend_ptr; + ++ mad_bit_init(&frameend_ptr, stream->next_frame); ++ ++ if (mad_bit_length(ptr, &frameend_ptr) < nb) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return 0; ++ } + sample = mad_bit_read(ptr, nb); + + /* invert most significant bit, extend sign, then scale to fixed format */ +@@ -106,6 +114,10 @@ int mad_layer_I(struct mad_stream *strea + struct mad_header *header = &frame->header; + unsigned int nch, bound, ch, s, sb, nb; + unsigned char allocation[2][32], scalefactor[2][32]; ++ struct mad_bitptr bufend_ptr, frameend_ptr; ++ ++ mad_bit_init(&bufend_ptr, stream->bufend); ++ mad_bit_init(&frameend_ptr, stream->next_frame); + + nch = MAD_NCHANNELS(header); + +@@ -118,6 +130,11 @@ int mad_layer_I(struct mad_stream *strea + /* check CRC word */ + + if (header->flags & MAD_FLAG_PROTECTION) { ++ if (mad_bit_length(&stream->ptr, &bufend_ptr) ++ < 4 * (bound * nch + (32 - bound))) { ++ stream->error = MAD_ERROR_BADCRC; ++ return -1; ++ } + header->crc_check = + mad_bit_crc(stream->ptr, 4 * (bound * nch + (32 - bound)), + header->crc_check); +@@ -133,6 +150,11 @@ int mad_layer_I(struct mad_stream *strea + + for (sb = 0; sb < bound; ++sb) { + for (ch = 0; ch < nch; ++ch) { ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 4) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + nb = mad_bit_read(&stream->ptr, 4); + + if (nb == 15) { +@@ -145,6 +167,11 @@ int mad_layer_I(struct mad_stream *strea + } + + for (sb = bound; sb < 32; ++sb) { ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 4) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + nb = mad_bit_read(&stream->ptr, 4); + + if (nb == 15) { +@@ -161,6 +188,11 @@ int mad_layer_I(struct mad_stream *strea + for (sb = 0; sb < 32; ++sb) { + for (ch = 0; ch < nch; ++ch) { + if (allocation[ch][sb]) { ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 6) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + scalefactor[ch][sb] = mad_bit_read(&stream->ptr, 6); + + # if defined(OPT_STRICT) +@@ -185,8 +217,10 @@ int mad_layer_I(struct mad_stream *strea + for (ch = 0; ch < nch; ++ch) { + nb = allocation[ch][sb]; + frame->sbsample[ch][s][sb] = nb ? +- mad_f_mul(I_sample(&stream->ptr, nb), ++ mad_f_mul(I_sample(&stream->ptr, nb, stream), + sf_table[scalefactor[ch][sb]]) : 0; ++ if (stream->error != 0) ++ return -1; + } + } + +@@ -194,7 +228,14 @@ int mad_layer_I(struct mad_stream *strea + if ((nb = allocation[0][sb])) { + mad_fixed_t sample; + +- sample = I_sample(&stream->ptr, nb); ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < nb) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } ++ sample = I_sample(&stream->ptr, nb, stream); ++ if (stream->error != 0) ++ return -1; + + for (ch = 0; ch < nch; ++ch) { + frame->sbsample[ch][s][sb] = +@@ -280,13 +321,21 @@ struct quantclass { + static + void II_samples(struct mad_bitptr *ptr, + struct quantclass const *quantclass, +- mad_fixed_t output[3]) ++ mad_fixed_t output[3], struct mad_stream *stream) + { + unsigned int nb, s, sample[3]; ++ struct mad_bitptr frameend_ptr; ++ ++ mad_bit_init(&frameend_ptr, stream->next_frame); + + if ((nb = quantclass->group)) { + unsigned int c, nlevels; + ++ if (mad_bit_length(ptr, &frameend_ptr) < quantclass->bits) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return; ++ } + /* degrouping */ + c = mad_bit_read(ptr, quantclass->bits); + nlevels = quantclass->nlevels; +@@ -299,8 +348,14 @@ void II_samples(struct mad_bitptr *ptr, + else { + nb = quantclass->bits; + +- for (s = 0; s < 3; ++s) ++ for (s = 0; s < 3; ++s) { ++ if (mad_bit_length(ptr, &frameend_ptr) < nb) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return; ++ } + sample[s] = mad_bit_read(ptr, nb); ++ } + } + + for (s = 0; s < 3; ++s) { +@@ -336,6 +391,9 @@ int mad_layer_II(struct mad_stream *stre + unsigned char const *offsets; + unsigned char allocation[2][32], scfsi[2][32], scalefactor[2][32][3]; + mad_fixed_t samples[3]; ++ struct mad_bitptr frameend_ptr; ++ ++ mad_bit_init(&frameend_ptr, stream->next_frame); + + nch = MAD_NCHANNELS(header); + +@@ -402,13 +460,24 @@ int mad_layer_II(struct mad_stream *stre + for (sb = 0; sb < bound; ++sb) { + nbal = bitalloc_table[offsets[sb]].nbal; + +- for (ch = 0; ch < nch; ++ch) ++ for (ch = 0; ch < nch; ++ch) { ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < nbal) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + allocation[ch][sb] = mad_bit_read(&stream->ptr, nbal); ++ } + } + + for (sb = bound; sb < sblimit; ++sb) { + nbal = bitalloc_table[offsets[sb]].nbal; + ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < nbal) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + allocation[0][sb] = + allocation[1][sb] = mad_bit_read(&stream->ptr, nbal); + } +@@ -417,8 +486,14 @@ int mad_layer_II(struct mad_stream *stre + + for (sb = 0; sb < sblimit; ++sb) { + for (ch = 0; ch < nch; ++ch) { +- if (allocation[ch][sb]) ++ if (allocation[ch][sb]) { ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 2) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + scfsi[ch][sb] = mad_bit_read(&stream->ptr, 2); ++ } + } + } + +@@ -441,6 +516,11 @@ int mad_layer_II(struct mad_stream *stre + for (sb = 0; sb < sblimit; ++sb) { + for (ch = 0; ch < nch; ++ch) { + if (allocation[ch][sb]) { ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 6) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + scalefactor[ch][sb][0] = mad_bit_read(&stream->ptr, 6); + + switch (scfsi[ch][sb]) { +@@ -451,11 +531,21 @@ int mad_layer_II(struct mad_stream *stre + break; + + case 0: ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 6) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + scalefactor[ch][sb][1] = mad_bit_read(&stream->ptr, 6); + /* fall through */ + + case 1: + case 3: ++ if (mad_bit_length(&stream->ptr, &frameend_ptr) < 6) { ++ stream->error = MAD_ERROR_LOSTSYNC; ++ stream->sync = 0; ++ return -1; ++ } + scalefactor[ch][sb][2] = mad_bit_read(&stream->ptr, 6); + } + +@@ -487,7 +577,9 @@ int mad_layer_II(struct mad_stream *stre + if ((index = allocation[ch][sb])) { + index = offset_table[bitalloc_table[offsets[sb]].offset][index - 1]; + +- II_samples(&stream->ptr, &qc_table[index], samples); ++ II_samples(&stream->ptr, &qc_table[index], samples, stream); ++ if (stream->error != 0) ++ return -1; + + for (s = 0; s < 3; ++s) { + frame->sbsample[ch][3 * gr + s][sb] = +@@ -505,7 +597,9 @@ int mad_layer_II(struct mad_stream *stre + if ((index = allocation[0][sb])) { + index = offset_table[bitalloc_table[offsets[sb]].offset][index - 1]; + +- II_samples(&stream->ptr, &qc_table[index], samples); ++ II_samples(&stream->ptr, &qc_table[index], samples, stream); ++ if (stream->error != 0) ++ return -1; + + for (ch = 0; ch < nch; ++ch) { + for (s = 0; s < 3; ++s) { +Index: libmad-0.15.1b/layer3.c +=================================================================== +--- libmad-0.15.1b.orig/layer3.c ++++ libmad-0.15.1b/layer3.c +@@ -598,7 +598,8 @@ enum mad_error III_sideinfo(struct mad_b + static + unsigned int III_scalefactors_lsf(struct mad_bitptr *ptr, + struct channel *channel, +- struct channel *gr1ch, int mode_extension) ++ struct channel *gr1ch, int mode_extension, ++ unsigned int bits_left, unsigned int *part2_length) + { + struct mad_bitptr start; + unsigned int scalefac_compress, index, slen[4], part, n, i; +@@ -644,8 +645,12 @@ unsigned int III_scalefactors_lsf(struct + + n = 0; + for (part = 0; part < 4; ++part) { +- for (i = 0; i < nsfb[part]; ++i) ++ for (i = 0; i < nsfb[part]; ++i) { ++ if (bits_left < slen[part]) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[n++] = mad_bit_read(ptr, slen[part]); ++ bits_left -= slen[part]; ++ } + } + + while (n < 39) +@@ -690,7 +695,10 @@ unsigned int III_scalefactors_lsf(struct + max = (1 << slen[part]) - 1; + + for (i = 0; i < nsfb[part]; ++i) { ++ if (bits_left < slen[part]) ++ return MAD_ERROR_BADSCFSI; + is_pos = mad_bit_read(ptr, slen[part]); ++ bits_left -= slen[part]; + + channel->scalefac[n] = is_pos; + gr1ch->scalefac[n++] = (is_pos == max); +@@ -703,7 +711,8 @@ unsigned int III_scalefactors_lsf(struct + } + } + +- return mad_bit_length(&start, ptr); ++ *part2_length = mad_bit_length(&start, ptr); ++ return MAD_ERROR_NONE; + } + + /* +@@ -712,7 +721,8 @@ unsigned int III_scalefactors_lsf(struct + */ + static + unsigned int III_scalefactors(struct mad_bitptr *ptr, struct channel *channel, +- struct channel const *gr0ch, unsigned int scfsi) ++ struct channel const *gr0ch, unsigned int scfsi, ++ unsigned int bits_left, unsigned int *part2_length) + { + struct mad_bitptr start; + unsigned int slen1, slen2, sfbi; +@@ -728,12 +738,20 @@ unsigned int III_scalefactors(struct mad + sfbi = 0; + + nsfb = (channel->flags & mixed_block_flag) ? 8 + 3 * 3 : 6 * 3; +- while (nsfb--) ++ while (nsfb--) { ++ if (bits_left < slen1) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[sfbi++] = mad_bit_read(ptr, slen1); ++ bits_left -= slen1; ++ } + + nsfb = 6 * 3; +- while (nsfb--) ++ while (nsfb--) { ++ if (bits_left < slen2) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[sfbi++] = mad_bit_read(ptr, slen2); ++ bits_left -= slen2; ++ } + + nsfb = 1 * 3; + while (nsfb--) +@@ -745,8 +763,12 @@ unsigned int III_scalefactors(struct mad + channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; + } + else { +- for (sfbi = 0; sfbi < 6; ++sfbi) ++ for (sfbi = 0; sfbi < 6; ++sfbi) { ++ if (bits_left < slen1) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[sfbi] = mad_bit_read(ptr, slen1); ++ bits_left -= slen1; ++ } + } + + if (scfsi & 0x4) { +@@ -754,8 +776,12 @@ unsigned int III_scalefactors(struct mad + channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; + } + else { +- for (sfbi = 6; sfbi < 11; ++sfbi) ++ for (sfbi = 6; sfbi < 11; ++sfbi) { ++ if (bits_left < slen1) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[sfbi] = mad_bit_read(ptr, slen1); ++ bits_left -= slen1; ++ } + } + + if (scfsi & 0x2) { +@@ -763,8 +789,12 @@ unsigned int III_scalefactors(struct mad + channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; + } + else { +- for (sfbi = 11; sfbi < 16; ++sfbi) ++ for (sfbi = 11; sfbi < 16; ++sfbi) { ++ if (bits_left < slen2) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[sfbi] = mad_bit_read(ptr, slen2); ++ bits_left -= slen2; ++ } + } + + if (scfsi & 0x1) { +@@ -772,14 +802,19 @@ unsigned int III_scalefactors(struct mad + channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; + } + else { +- for (sfbi = 16; sfbi < 21; ++sfbi) ++ for (sfbi = 16; sfbi < 21; ++sfbi) { ++ if (bits_left < slen2) ++ return MAD_ERROR_BADSCFSI; + channel->scalefac[sfbi] = mad_bit_read(ptr, slen2); ++ bits_left -= slen2; ++ } + } + + channel->scalefac[21] = 0; + } + +- return mad_bit_length(&start, ptr); ++ *part2_length = mad_bit_length(&start, ptr); ++ return MAD_ERROR_NONE; + } + + /* +@@ -933,19 +968,17 @@ static + enum mad_error III_huffdecode(struct mad_bitptr *ptr, mad_fixed_t xr[576], + struct channel *channel, + unsigned char const *sfbwidth, +- unsigned int part2_length) ++ signed int part3_length) + { + signed int exponents[39], exp; + signed int const *expptr; + struct mad_bitptr peek; +- signed int bits_left, cachesz; ++ signed int bits_left, cachesz, fakebits; + register mad_fixed_t *xrptr; + mad_fixed_t const *sfbound; + register unsigned long bitcache; + +- bits_left = (signed) channel->part2_3_length - (signed) part2_length; +- if (bits_left < 0) +- return MAD_ERROR_BADPART3LEN; ++ bits_left = part3_length; + + III_exponents(channel, sfbwidth, exponents); + +@@ -956,8 +989,12 @@ enum mad_error III_huffdecode(struct mad + cachesz = mad_bit_bitsleft(&peek); + cachesz += ((32 - 1 - 24) + (24 - cachesz)) & ~7; + ++ if (bits_left < cachesz) { ++ cachesz = bits_left; ++ } + bitcache = mad_bit_read(&peek, cachesz); + bits_left -= cachesz; ++ fakebits = 0; + + xrptr = &xr[0]; + +@@ -986,7 +1023,7 @@ enum mad_error III_huffdecode(struct mad + + big_values = channel->big_values; + +- while (big_values-- && cachesz + bits_left > 0) { ++ while (big_values-- && cachesz + bits_left - fakebits > 0) { + union huffpair const *pair; + unsigned int clumpsz, value; + register mad_fixed_t requantized; +@@ -1023,10 +1060,19 @@ enum mad_error III_huffdecode(struct mad + unsigned int bits; + + bits = ((32 - 1 - 21) + (21 - cachesz)) & ~7; ++ if (bits_left < bits) { ++ bits = bits_left; ++ } + bitcache = (bitcache << bits) | mad_bit_read(&peek, bits); + cachesz += bits; + bits_left -= bits; + } ++ if (cachesz < 21) { ++ unsigned int bits = 21 - cachesz; ++ bitcache <<= bits; ++ cachesz += bits; ++ fakebits += bits; ++ } + + /* hcod (0..19) */ + +@@ -1041,6 +1087,8 @@ enum mad_error III_huffdecode(struct mad + } + + cachesz -= pair->value.hlen; ++ if (cachesz < fakebits) ++ return MAD_ERROR_BADHUFFDATA; + + if (linbits) { + /* x (0..14) */ +@@ -1054,10 +1102,15 @@ enum mad_error III_huffdecode(struct mad + + case 15: + if (cachesz < linbits + 2) { +- bitcache = (bitcache << 16) | mad_bit_read(&peek, 16); +- cachesz += 16; +- bits_left -= 16; ++ unsigned int bits = 16; ++ if (bits_left < 16) ++ bits = bits_left; ++ bitcache = (bitcache << bits) | mad_bit_read(&peek, bits); ++ cachesz += bits; ++ bits_left -= bits; + } ++ if (cachesz - fakebits < linbits) ++ return MAD_ERROR_BADHUFFDATA; + + value += MASK(bitcache, cachesz, linbits); + cachesz -= linbits; +@@ -1074,6 +1127,8 @@ enum mad_error III_huffdecode(struct mad + } + + x_final: ++ if (cachesz - fakebits < 1) ++ return MAD_ERROR_BADHUFFDATA; + xrptr[0] = MASK1BIT(bitcache, cachesz--) ? + -requantized : requantized; + } +@@ -1089,10 +1144,15 @@ enum mad_error III_huffdecode(struct mad + + case 15: + if (cachesz < linbits + 1) { +- bitcache = (bitcache << 16) | mad_bit_read(&peek, 16); +- cachesz += 16; +- bits_left -= 16; ++ unsigned int bits = 16; ++ if (bits_left < 16) ++ bits = bits_left; ++ bitcache = (bitcache << bits) | mad_bit_read(&peek, bits); ++ cachesz += bits; ++ bits_left -= bits; + } ++ if (cachesz - fakebits < linbits) ++ return MAD_ERROR_BADHUFFDATA; + + value += MASK(bitcache, cachesz, linbits); + cachesz -= linbits; +@@ -1109,6 +1169,8 @@ enum mad_error III_huffdecode(struct mad + } + + y_final: ++ if (cachesz - fakebits < 1) ++ return MAD_ERROR_BADHUFFDATA; + xrptr[1] = MASK1BIT(bitcache, cachesz--) ? + -requantized : requantized; + } +@@ -1128,6 +1190,8 @@ enum mad_error III_huffdecode(struct mad + requantized = reqcache[value] = III_requantize(value, exp); + } + ++ if (cachesz - fakebits < 1) ++ return MAD_ERROR_BADHUFFDATA; + xrptr[0] = MASK1BIT(bitcache, cachesz--) ? + -requantized : requantized; + } +@@ -1146,6 +1210,8 @@ enum mad_error III_huffdecode(struct mad + requantized = reqcache[value] = III_requantize(value, exp); + } + ++ if (cachesz - fakebits < 1) ++ return MAD_ERROR_BADHUFFDATA; + xrptr[1] = MASK1BIT(bitcache, cachesz--) ? + -requantized : requantized; + } +@@ -1155,9 +1221,6 @@ enum mad_error III_huffdecode(struct mad + } + } + +- if (cachesz + bits_left < 0) +- return MAD_ERROR_BADHUFFDATA; /* big_values overrun */ +- + /* count1 */ + { + union huffquad const *table; +@@ -1167,15 +1230,24 @@ enum mad_error III_huffdecode(struct mad + + requantized = III_requantize(1, exp); + +- while (cachesz + bits_left > 0 && xrptr <= &xr[572]) { ++ while (cachesz + bits_left - fakebits > 0 && xrptr <= &xr[572]) { + union huffquad const *quad; + + /* hcod (1..6) */ + + if (cachesz < 10) { +- bitcache = (bitcache << 16) | mad_bit_read(&peek, 16); +- cachesz += 16; +- bits_left -= 16; ++ unsigned int bits = 16; ++ if (bits_left < 16) ++ bits = bits_left; ++ bitcache = (bitcache << bits) | mad_bit_read(&peek, bits); ++ cachesz += bits; ++ bits_left -= bits; ++ } ++ if (cachesz < 10) { ++ unsigned int bits = 10 - cachesz; ++ bitcache <<= bits; ++ cachesz += bits; ++ fakebits += bits; + } + + quad = &table[MASK(bitcache, cachesz, 4)]; +@@ -1188,6 +1260,11 @@ enum mad_error III_huffdecode(struct mad + MASK(bitcache, cachesz, quad->ptr.bits)]; + } + ++ if (cachesz - fakebits < quad->value.hlen + quad->value.v ++ + quad->value.w + quad->value.x + quad->value.y) ++ /* We don't have enough bits to read one more entry, consider them ++ * stuffing bits. */ ++ break; + cachesz -= quad->value.hlen; + + if (xrptr == sfbound) { +@@ -1236,22 +1313,8 @@ enum mad_error III_huffdecode(struct mad + + xrptr += 2; + } +- +- if (cachesz + bits_left < 0) { +-# if 0 && defined(DEBUG) +- fprintf(stderr, "huffman count1 overrun (%d bits)\n", +- -(cachesz + bits_left)); +-# endif +- +- /* technically the bitstream is misformatted, but apparently +- some encoders are just a bit sloppy with stuffing bits */ +- +- xrptr -= 4; +- } + } + +- assert(-bits_left <= MAD_BUFFER_GUARD * CHAR_BIT); +- + # if 0 && defined(DEBUG) + if (bits_left < 0) + fprintf(stderr, "read %d bits too many\n", -bits_left); +@@ -2348,10 +2411,11 @@ void III_freqinver(mad_fixed_t sample[18 + */ + static + enum mad_error III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, +- struct sideinfo *si, unsigned int nch) ++ struct sideinfo *si, unsigned int nch, unsigned int md_len) + { + struct mad_header *header = &frame->header; + unsigned int sfreqi, ngr, gr; ++ int bits_left = md_len * CHAR_BIT; + + { + unsigned int sfreq; +@@ -2383,6 +2447,7 @@ enum mad_error III_decode(struct mad_bit + for (ch = 0; ch < nch; ++ch) { + struct channel *channel = &granule->ch[ch]; + unsigned int part2_length; ++ unsigned int part3_length; + + sfbwidth[ch] = sfbwidth_table[sfreqi].l; + if (channel->block_type == 2) { +@@ -2391,18 +2456,30 @@ enum mad_error III_decode(struct mad_bit + } + + if (header->flags & MAD_FLAG_LSF_EXT) { +- part2_length = III_scalefactors_lsf(ptr, channel, ++ error = III_scalefactors_lsf(ptr, channel, + ch == 0 ? 0 : &si->gr[1].ch[1], +- header->mode_extension); ++ header->mode_extension, bits_left, &part2_length); + } + else { +- part2_length = III_scalefactors(ptr, channel, &si->gr[0].ch[ch], +- gr == 0 ? 0 : si->scfsi[ch]); ++ error = III_scalefactors(ptr, channel, &si->gr[0].ch[ch], ++ gr == 0 ? 0 : si->scfsi[ch], bits_left, &part2_length); + } ++ if (error) ++ return error; ++ ++ bits_left -= part2_length; + +- error = III_huffdecode(ptr, xr[ch], channel, sfbwidth[ch], part2_length); ++ if (part2_length > channel->part2_3_length) ++ return MAD_ERROR_BADPART3LEN; ++ ++ part3_length = channel->part2_3_length - part2_length; ++ if (part3_length > bits_left) ++ return MAD_ERROR_BADPART3LEN; ++ ++ error = III_huffdecode(ptr, xr[ch], channel, sfbwidth[ch], part3_length); + if (error) + return error; ++ bits_left -= part3_length; + } + + /* joint stereo processing */ +@@ -2519,11 +2596,13 @@ int mad_layer_III(struct mad_stream *str + unsigned int nch, priv_bitlen, next_md_begin = 0; + unsigned int si_len, data_bitlen, md_len; + unsigned int frame_space, frame_used, frame_free; +- struct mad_bitptr ptr; ++ struct mad_bitptr ptr, bufend_ptr; + struct sideinfo si; + enum mad_error error; + int result = 0; + ++ mad_bit_init(&bufend_ptr, stream->bufend); ++ + /* allocate Layer III dynamic structures */ + + if (stream->main_data == 0) { +@@ -2587,14 +2666,15 @@ int mad_layer_III(struct mad_stream *str + unsigned long header; + + mad_bit_init(&peek, stream->next_frame); ++ if (mad_bit_length(&peek, &bufend_ptr) >= 57) { ++ header = mad_bit_read(&peek, 32); ++ if ((header & 0xffe60000L) /* syncword | layer */ == 0xffe20000L) { ++ if (!(header & 0x00010000L)) /* protection_bit */ ++ mad_bit_skip(&peek, 16); /* crc_check */ + +- header = mad_bit_read(&peek, 32); +- if ((header & 0xffe60000L) /* syncword | layer */ == 0xffe20000L) { +- if (!(header & 0x00010000L)) /* protection_bit */ +- mad_bit_skip(&peek, 16); /* crc_check */ +- +- next_md_begin = +- mad_bit_read(&peek, (header & 0x00080000L) /* ID */ ? 9 : 8); ++ next_md_begin = ++ mad_bit_read(&peek, (header & 0x00080000L) /* ID */ ? 9 : 8); ++ } + } + + mad_bit_finish(&peek); +@@ -2653,7 +2733,7 @@ int mad_layer_III(struct mad_stream *str + /* decode main_data */ + + if (result == 0) { +- error = III_decode(&ptr, frame, &si, nch); ++ error = III_decode(&ptr, frame, &si, nch, md_len); + if (error) { + stream->error = error; + result = -1; -- cgit v1.2.3-60-g2f50