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Merge pull request #1436 from nickaein/iterate-on-destruction

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Prevent stackoverflow caused by recursive deconstruction
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Niels Lohmann 2019-11-10 11:57:06 +01:00 committed by GitHub
commit 0a513a35cb
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4 changed files with 148 additions and 0 deletions
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49
include/nlohmann/json.hpp
View file

@ -998,6 +998,55 @@ class basic_json
void destroy(value_t t) noexcept
{
// flatten the current json_value to a heap-allocated stack
std::vector<basic_json> stack;
// move the top-level items to stack
if (t == value_t::array)
{
stack.reserve(array->size());
std::move(array->begin(), array->end(), std::back_inserter(stack));
}
else if (t == value_t::object)
{
stack.reserve(object->size());
for (auto&& it : *object)
{
stack.push_back(std::move(it.second));
}
}
while (!stack.empty())
{
// move the last item to local variable to be processed
basic_json current_item(std::move(stack.back()));
stack.pop_back();
// if current_item is array/object, move
// its children to the stack to be processed later
if (current_item.is_array())
{
stack.reserve(stack.size() + current_item.m_value.array->size());
std::move(current_item.m_value.array->begin(), current_item.m_value.array->end(),
std::back_inserter(stack));
current_item.m_value.array->clear();
}
else if (current_item.is_object())
{
stack.reserve(stack.size() + current_item.m_value.object->size());
for (auto&& it : *current_item.m_value.object)
{
stack.push_back(std::move(it.second));
}
}
// current_item is destroyed here
}
switch (t)
{
case value_t::object:

49
single_include/nlohmann/json.hpp
View file

@ -15541,6 +15541,55 @@ class basic_json
void destroy(value_t t) noexcept
{
// flatten the current json_value to a heap-allocated stack
std::vector<basic_json> stack;
// move the top-level items to stack
if (t == value_t::array)
{
stack.reserve(array->size());
std::move(array->begin(), array->end(), std::back_inserter(stack));
}
else if (t == value_t::object)
{
stack.reserve(object->size());
for (auto&& it : *object)
{
stack.push_back(std::move(it.second));
}
}
while (!stack.empty())
{
// move the last item to local variable to be processed
basic_json current_item(std::move(stack.back()));
stack.pop_back();
// if current_item is array/object, move
// its children to the stack to be processed later
if (current_item.is_array())
{
stack.reserve(stack.size() + current_item.m_value.array->size());
std::move(current_item.m_value.array->begin(), current_item.m_value.array->end(),
std::back_inserter(stack));
current_item.m_value.array->clear();
}
else if (current_item.is_object())
{
stack.reserve(stack.size() + current_item.m_value.object->size());
for (auto&& it : *current_item.m_value.object)
{
stack.push_back(std::move(it.second));
}
}
// current_item is destroyed here
}
switch (t)
{
case value_t::object:

1
test/CMakeLists.txt
View file

@ -127,6 +127,7 @@ set(files
src/unit-iterators2.cpp
src/unit-json_patch.cpp
src/unit-json_pointer.cpp
src/unit-large_json.cpp
src/unit-merge_patch.cpp
src/unit-meta.cpp
src/unit-modifiers.cpp

49
test/src/unit-large_json.cpp Normal file
View file

@ -0,0 +1,49 @@
/*
__ _____ _____ _____
__| | __| | | | JSON for Modern C++ (test suite)
| | |__ | | | | | | version 3.7.1
|_____|_____|_____|_|___| https://github.com/nlohmann/json
Licensed under the MIT License <http://opensource.org/licenses/MIT>.
SPDX-License-Identifier: MIT
Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include "doctest_compatibility.h"
#include <nlohmann/json.hpp>
using nlohmann::json;
#include <algorithm>
TEST_CASE("tests on very large JSONs")
{
SECTION("issue #1419 - Segmentation fault (stack overflow) due to unbounded recursion")
{
const auto depth = 5000000;
std::string s(2 * depth, '[');
std::fill(s.begin() + depth, s.end(), ']');
CHECK_NOTHROW(nlohmann::json::parse(s));
}
}