Undefined behavior

[Loki-Astari]

ujson/ujson/ujson.hpp

Lines 514 to 517 in 2b17263

	inline value::value(value &&rhs) noexcept {
	std::memcpy(m_storage, rhs.m_storage, storage_size);
	new (rhs.m_storage)null_impl_t{};
	}

The use of memcpy() in the value constructors is undefined behavior. You are assuming that these objects don't have internal references (or in the case of std::shared_ptr external references). C++ objects can not simply be copied by using memcpy they should be copied using the copy of move constructor.

Issues are:

inline value::value(value &&rhs) noexcept
inline value &value::operator=(string const &s)
inline value &value::operator=(string &&s)
inline value &value::operator=(array const &a)
inline value &value::operator=(array &&a)
inline value &value::operator=(object const &o)
inline value &value::operator=(object &&o)
inline value &value::operator=(value &&rhs) noexcept
inline void value::swap(value &other) noexcept

The following json files when read into value object will cause a crash (caused by bad call to free()).

• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_pass/pass01.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_pass/pass02.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_fail/fail02.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_fail/fail04.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_fail/fail08.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_fail/fail23.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/jsonchecker_fail/fail33.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/performance/canada.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/performance/citm_catalog.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/performance/twitter.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/roundtrip/roundtrip05.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/roundtrip/roundtrip09.json
• https://raw.githubusercontent.com/Loki-Astari/JsonBenchmark/master/data/roundtrip/roundtrip10.json

Note: This builds and works fine on my apple (OS-X 10.15.5)
But fails on Linux (Ubuntu 18.04)