Memory leak vulnerability in try-catch in walletconsole/Util.cpp

[brutalsavage]

Describe the bug
buffer is allocated in try block however there is no delete call for deallocation in catch block for if the exception is thrown after the buffer allocation. If the exception is thrown after new there is a memory leak. Potential exception can be thrown from infile.gcount() or infile.close() .

This is similar to #921 except the missing delete is in the catch block.

[optout21]

@brutalsavage , could you specify the source file location? thanks

[brutalsavage]

@catenocrypt here is the vulnerable function

wallet-core/walletconsole/lib/Util.cpp

Lines 68 to 95 in 883e0e5

	bool Util::fileR(const string& fileName, string& res) {
	if (!fileExists(fileName)) {
	_out << "Error: File not found '" << fileName << "'" << endl;
	return false;
	}
	try {
	ifstream infile(fileName, std::ios::in | std::ios::binary);
	// get length of file:
	infile.seekg (0, infile.end);
	auto length = infile.tellg();
	infile.seekg (0, infile.beg);
	char* buffer = new char[length];
	if (!infile.read(buffer, length)) {
	_out << "Could not read file '" << fileName << "'" << endl;
	delete[] buffer;
	return false;
	}
	auto red = infile.gcount();
	infile.close();
	res = string(TW::hex(data((const byte*)buffer, red)));
	delete[] buffer;
	_out << "Read " << red << " bytes from file '" << fileName << "'." << endl;
	return true;
	} catch (exception& ex) {
	_out << "Error reading from file '" << fileName << "': " << ex.what() << endl;
	return false;
	}
	}

[brutalsavage]

@catenocrypt Hi! Thanks for taking a look at this and fixing it. This vulnerability was detected by our deep learning based vulnerability detection model. Along with the detection, our model also localizes the vulnerability by producing a version of the function with code that contributed to the vulnerability highlighted. We provide the localization output of the vulnerable function identified in this Issue. The intensity of the highlight correspond to how important the code snippet was for vulnerability detection in this function.

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