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🚑 fix to address #389

pull/390/head
Niels Lohmann 2016-12-12 23:19:43 +01:00
parent 447e01427d
commit 79fa8b2f41
3 changed files with 49 additions and 2 deletions
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17
src/json.hpp
View File

@ -10643,7 +10643,22 @@ basic_json_parser_66:
}
else if (type == value_t::number_integer)
{
result.m_value.number_integer = -static_cast<number_integer_t>(value);
// invariant: if we parsed a '-', the absolute value is between
// 0 (we allow -0) and max == -INT64_MIN
assert(value >= 0);
assert(value <= max);
if (value == max)
{
// we cannot simply negate value (== max == -INT64_MIN),
// see https://github.com/nlohmann/json/issues/389
result.m_value.number_integer = INT64_MIN;
}
else
{
// all other values can be negated safely
result.m_value.number_integer = -static_cast<number_integer_t>(value);
}
}
else
{

17
src/json.hpp.re2c
View File

@ -9793,7 +9793,22 @@ class basic_json
}
else if (type == value_t::number_integer)
{
result.m_value.number_integer = -static_cast<number_integer_t>(value);
// invariant: if we parsed a '-', the absolute value is between
// 0 (we allow -0) and max == -INT64_MIN
assert(value >= 0);
assert(value <= max);
if (value == max)
{
// we cannot simply negate value (== max == -INT64_MIN),
// see https://github.com/nlohmann/json/issues/389
result.m_value.number_integer = INT64_MIN;
}
else
{
// all other values can be negated safely
result.m_value.number_integer = -static_cast<number_integer_t>(value);
}
}
else
{

17
test/src/unit-regression.cpp
View File

@ -516,4 +516,21 @@ TEST_CASE("regression tests")
CHECK_THROWS_AS(j << ss, std::invalid_argument);
CHECK_THROWS_WITH(j << ss, "parse error - unexpected end of input");
}
SECTION("issue #389 - Integer-overflow (OSS-Fuzz issue 267)")
{
// original test case
json j1 = json::parse("-9223372036854775808");
CHECK(j1.is_number_integer());
CHECK(j1.get<json::number_integer_t>() == INT64_MIN);
// edge case (+1; still an integer)
json j2 = json::parse("-9223372036854775807");
CHECK(j2.is_number_integer());
CHECK(j2.get<json::number_integer_t>() == INT64_MIN + 1);
// edge case (-1; overflow -> floats)
json j3 = json::parse("-9223372036854775809");
CHECK(j3.is_number_float());
}
}