nooneuse commented on code in PR #69257: URL: https://github.com/apache/doris/pull/69257#discussion_r4325652559
########## be/src/exprs/datasketches_hll_util.cpp: ########## @@ -0,0 +1,79 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#include "exprs/datasketches_hll_util.h" + +#include <cstring> +#include <exception> +#include <stdexcept> + +#include "common/exception.h" +#include "common/status.h" + +namespace doris::datasketches_hll { + +Sketch deserialize(const StringRef& value, std::string_view action) { + // The library reads the preamble byte before it checks the length. + if (value.size == 0) { + throw Exception(ErrorCode::CORRUPTION, "HLL sketch data corrupted when {}: empty input.", + action); + } + try { + // All modes have an eight-byte preamble. An invalid lgK would otherwise reach shifts used + // to size the register/coupon arrays before the library validates it. + datasketches::HllUtil<Alloc>::checkMemSize( + datasketches::hll_constants::EMPTY_SKETCH_SIZE_BYTES, value.size); + datasketches::HllUtil<Alloc>::checkLgK( + static_cast<uint8_t>(value.data[datasketches::hll_constants::LG_K_BYTE])); + // HLL_4 uses nibble 0xf to reference its auxiliary map. The library accepts an image + // with auxCount=0 and such a nibble, then dereferences a null map during union/conversion. + // This occurs, for example, when UTF-8 replacement bytes shift a binary sketch's fields. + // Validate this structural invariant before exposing the sketch, including on a no-op. + using namespace datasketches::hll_constants; + const auto* bytes = reinterpret_cast<const uint8_t*>(value.data); + const bool is_hll4 = bytes[PREAMBLE_INTS_BYTE] == HLL_PREINTS && + (bytes[MODE_BYTE] & loNibbleMask) == datasketches::hll_mode::HLL; + if (is_hll4) { + const size_t register_bytes = size_t {1} << (bytes[LG_K_BYTE] - 1); + datasketches::HllUtil<Alloc>::checkMemSize(HLL_BYTE_ARR_START + register_bytes, + value.size); + uint32_t aux_count = 0; + std::memcpy(&aux_count, bytes + AUX_COUNT_INT, sizeof(aux_count)); + if (aux_count == 0) { + for (size_t i = HLL_BYTE_ARR_START; i < HLL_BYTE_ARR_START + register_bytes; ++i) { + if ((bytes[i] & loNibbleMask) == AUX_TOKEN || + ((bytes[i] >> 4) & loNibbleMask) == AUX_TOKEN) { + throw std::invalid_argument( + "HLL_4 contains AUX_TOKEN without an auxiliary map"); + } + } + } + } + return Sketch::deserialize(value.data, value.size, Alloc()); Review Comment: OK, I'll fix it. However, the root cause of this issue is that the serialization/deserialization in the Datasketches library does not adequately guard against dirty data. I will add protection on the Doris side and later push the Datasketches community to incorporate this defense into the library. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
