From afb2aa537954db537d54358997b68f46561fd5a7 Mon Sep 17 00:00:00 2001 From: Chris Evans Date: Thu, 5 Jan 2012 21:25:41 +0100 Subject: vorbis: An additional defense in the Vorbis codec. Fixes Bug: #190 Chromium Bug: #100543 Related to CVE-2011-3893 Signed-off-by: Reinhard Tartler --- libavcodec/vorbisdec.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) (limited to 'libavcodec/vorbisdec.c') diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c index dd30c0fe7a..bb69fed254 100644 --- a/libavcodec/vorbisdec.c +++ b/libavcodec/vorbisdec.c @@ -1281,6 +1281,7 @@ static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc, uint8_t *do_not_decode, float *vec, unsigned vlen, + unsigned ch_left, int vr_type) { GetBitContext *gb = &vc->gb; @@ -1288,6 +1289,7 @@ static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc, unsigned ptns_to_read = vr->ptns_to_read; uint8_t *classifs = vr->classifs; unsigned pass, ch_used, i, j, k, l; + unsigned max_output = (ch - 1) * vlen; if (vr_type == 2) { for (j = 1; j < ch; ++j) @@ -1295,8 +1297,15 @@ static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc, if (do_not_decode[0]) return 0; ch_used = 1; + max_output += vr->end / ch; } else { ch_used = ch; + max_output += vr->end; + } + + if (max_output > ch_left * vlen) { + av_log(vc->avccontext, AV_LOG_ERROR, "Insufficient output buffer\n"); + return -1; } av_dlog(NULL, " residue type 0/1/2 decode begin, ch: %d cpc %d \n", ch, c_p_c); @@ -1423,14 +1432,15 @@ static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc, static inline int vorbis_residue_decode(vorbis_context *vc, vorbis_residue *vr, unsigned ch, uint8_t *do_not_decode, - float *vec, unsigned vlen) + float *vec, unsigned vlen, + unsigned ch_left) { if (vr->type == 2) - return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, 2); + return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, ch_left, 2); else if (vr->type == 1) - return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, 1); + return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, ch_left, 1); else if (vr->type == 0) - return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, 0); + return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, ch_left, 0); else { av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n"); return AVERROR_INVALIDDATA; @@ -1478,7 +1488,8 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) uint8_t res_chan[255]; unsigned res_num = 0; int retlen = 0; - int ch_left = vc->audio_channels; + unsigned ch_left = vc->audio_channels; + unsigned vlen; if (get_bits1(gb)) { av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n"); @@ -1498,11 +1509,12 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) blockflag = vc->modes[mode_number].blockflag; blocksize = vc->blocksize[blockflag]; + vlen = blocksize / 2; if (blockflag) skip_bits(gb, 2); // previous_window, next_window - memset(ch_res_ptr, 0, sizeof(float) * vc->audio_channels * blocksize / 2); //FIXME can this be removed ? - memset(ch_floor_ptr, 0, sizeof(float) * vc->audio_channels * blocksize / 2); //FIXME can this be removed ? + memset(ch_res_ptr, 0, sizeof(float) * vc->audio_channels * vlen); //FIXME can this be removed ? + memset(ch_floor_ptr, 0, sizeof(float) * vc->audio_channels * vlen); //FIXME can this be removed ? // Decode floor @@ -1522,7 +1534,7 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) return AVERROR_INVALIDDATA; } no_residue[i] = ret; - ch_floor_ptr += blocksize / 2; + ch_floor_ptr += vlen; } // Nonzero vector propagate @@ -1539,6 +1551,7 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) for (i = 0; i < mapping->submaps; ++i) { vorbis_residue *residue; unsigned ch = 0; + int ret; for (j = 0; j < vc->audio_channels; ++j) { if ((mapping->submaps == 1) || (i == mapping->mux[j])) { @@ -1557,9 +1570,13 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) av_log(vc->avccontext, AV_LOG_ERROR, "Too many channels in vorbis_floor_decode.\n"); return -1; } - vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2); + if (ch) { + ret = vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, vlen, ch_left); + if (ret < 0) + return ret; + } - ch_res_ptr += ch * blocksize / 2; + ch_res_ptr += ch * vlen; ch_left -= ch; } -- cgit v1.2.3