Commit message: src/libFLAC/stream_decoder.c : Fail safely to avoid a heap overflow.

This fix is closely related to the fix for CVE-2014-9028. When that
fix went public Miroslav Lichvar noticed a similar potential problem
spot in the same function and was able to craft a file to trigger a
heap write overflow.

Reported-by : Miroslav Lichvar <mlichvar@redhat.com>
CVE: CVE-2014-9028
CWE: CWE-119
Vulnerability description: Heap-based buffer overflow in stream_decoder.c in libFLAC before 1.3.1 allows remote attackers to execute arbitrary code via a crafted .flac file.

Project: flac
File: stream_decoder.c

FLAC__bool read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order, FLAC__EntropyCodingMethod_PartitionedRiceContents *partitioned_rice_contents, FLAC__int32 *residual, FLAC__bool is_extended)
{
	FLAC__uint32 rice_parameter;
	int i;
	unsigned partition, sample, u;
	const unsigned partitions = 1u << partition_order;
	const unsigned partition_samples = partition_order > 0? decoder->private_->frame.header.blocksize >> partition_order : decoder->private_->frame.header.blocksize - predictor_order;
	const unsigned plen = is_extended? FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN : FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN;
	const unsigned pesc = is_extended? FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_ESCAPE_PARAMETER : FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER;

	/* sanity checks */
	if(partition_order == 0) {
		if(decoder->private_->frame.header.blocksize < predictor_order) {
			send_error_to_client_(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC);
			decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			/* We have received a potentially malicious bit stream. All we can do is error out to avoid a heap overflow. */
			return false;
		}
	}
	else {
		if(partition_samples < predictor_order) {
			send_error_to_client_(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC);
			decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			return true;
		}
	}

	if(!FLAC__format_entropy_coding_method_partitioned_rice_contents_ensure_size(partitioned_rice_contents, flac_max(6u, partition_order))) {
		decoder->protected_->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
		return false;
	}

	sample = 0;
	for(partition = 0; partition < partitions; partition++) {
		if(!FLAC__bitreader_read_raw_uint32(decoder->private_->input, &rice_parameter, plen))
			return false; /* read_callback_ sets the state for us */
		partitioned_rice_contents->parameters[partition] = rice_parameter;
		if(rice_parameter < pesc) {
			partitioned_rice_contents->raw_bits[partition] = 0;
			u = (partition_order == 0 || partition > 0)? partition_samples : partition_samples - predictor_order;
			if(!FLAC__bitreader_read_rice_signed_block(decoder->private_->input, residual + sample, u, rice_parameter))
				return false; /* read_callback_ sets the state for us */
			sample += u;
		}
		else {
			if(!FLAC__bitreader_read_raw_uint32(decoder->private_->input, &rice_parameter, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN))
				return false; /* read_callback_ sets the state for us */
			partitioned_rice_contents->raw_bits[partition] = rice_parameter;
			for(u = (partition_order == 0 || partition > 0)? 0 : predictor_order; u < partition_samples; u++, sample++) {
				if(!FLAC__bitreader_read_raw_int32(decoder->private_->input, &i, rice_parameter))
					return false; /* read_callback_ sets the state for us */
				residual[sample] = i;
			}
		}
	}

	return true;
}