From 42f0a6696889ba275aa2087b57fa99f7a97033a0 Mon Sep 17 00:00:00 2001 From: Reinhard Tartler Date: Thu, 5 Jan 2012 21:40:18 +0100 Subject: [PATCH] vorbisdec: Fix decoding bug with channel handling Fixes Bug: #191 Chromium Bug: #101458 CVE-2011-3895 Signed-off-by: Reinhard Tartler (cherry picked from commit e6d527ff729e42d80e4756cab779ff4ad693631b) Signed-off-by: Reinhard Tartler (cherry picked from commit 97f23c72a3815739ab28e297ce60f943349f6939) Conflicts: libavcodec/vorbis_dec.c --- libavcodec/vorbis_dec.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/libavcodec/vorbis_dec.c b/libavcodec/vorbis_dec.c index f8067db41c..4910860167 100644 --- a/libavcodec/vorbis_dec.c +++ b/libavcodec/vorbis_dec.c @@ -656,7 +656,7 @@ static int vorbis_parse_setup_hdr_residues(vorbis_context *vc) res_setup->partition_size = get_bits(gb, 24) + 1; /* Validations to prevent a buffer overflow later. */ if (res_setup->begin>res_setup->end || - res_setup->end>vc->blocksize[1] / (res_setup->type == 2 ? 1 : 2) || + res_setup->end > (res_setup->type == 2 ? vc->avccontext->channels : 1) * vc->blocksize[1] / 2 || (res_setup->end-res_setup->begin) / res_setup->partition_size > V_MAX_PARTITIONS) { av_log(vc->avccontext, AV_LOG_ERROR, "partition out of bounds: type, begin, end, size, blocksize: %"PRIdFAST16", %"PRIdFAST32", %"PRIdFAST32", %"PRIdFAST32", %"PRIdFAST32"\n", res_setup->type, res_setup->begin, res_setup->end, res_setup->partition_size, vc->blocksize[1] / 2); return -1; @@ -1473,6 +1473,7 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) uint_fast8_t res_num = 0; int_fast16_t retlen = 0; float fadd_bias = vc->add_bias; + int ch_left = vc->audio_channels; if (get_bits1(gb)) { av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n"); @@ -1546,9 +1547,14 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) } } residue = &vc->residues[mapping->submap_residue[i]]; + if (ch_left < ch) { + 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); ch_res_ptr += ch * blocksize / 2; + ch_left -= ch; } // Inverse coupling