Reader segfaults while parsing a huge array

[0xbb]

Hi! I was testing a library using jsoncpp and I encountered that using a crafted JSON file can lead to a segfault in the JSON Reader.
I used the following command to generate a huge nested array (valid JSON) that causes jstontestrunner_exe to crash:

 python -c "i=99999; print '['*i + '666' + ']'*i" > out.json;

[cdunn2001]

I like your testcase.

The sweet spot for jsoncpp is moderate sized configuration data (with comments) so I'm not too worried about extremes. But if you find the bug -- or at least turn the segfault into an exception -- we'd gladly accept a pull request, Mr. 0273.

[BillyDonahue]

Just to clarify, the problem isn't the size, but the deep nesting.
I reproduced it on MacOS, and the deep recursion is busting the stack about 18,000 levels deep.

...
frame #36141:Json::Reader::readValue() + 343
frame #36142:Json::Reader::readArray(Json::Reader::Token&) + 418
frame #36143:Json::Reader::readValue() + 343
frame #36144:Json::Reader::readArray(Json::Reader::Token&) + 418
frame #36145:Json::Reader::readValue() + 343
frame #36146:Json::Reader::readArray(Json::Reader::Token&) + 418
frame #36147:Json::Reader::readValue() + 343
frame #36148:Json::Reader::readArray(Json::Reader::Token&) + 418
frame #36149:Json::Reader::readValue() + 343
frame #36150:Json::Reader::readArray(Json::Reader::Token&) + 418
frame #36151:Json::Reader::readValue() + 343
frame #36152:Json::Reader::parse(char const_, char const_, Json::Value&, bool) + 352
frame #36153:parseAndSaveValueTree(std::string const&, std::string const&, std::string const&, Json::Value&, Json::Features const&, bool) + 79

[0xbb]

@cdunn2001 I am glad you like it :)

It's definitely the limited stack size.
Under Linux you can tune stack size with:
ulimit -s unlimited
and the error will go away.
This is of course no solution! Other JSON parsers sometimes have a limited nested depth to prevent this kind of problems. To be honest I don't have really insights in jsoncpp's code and how to best fix this issue.

[cdunn2001]

Removing the recursion would be a big change. I don't think we will fix this. But feel free to update the wiki so that others do not run into the same problem.