oss-fuzz VS clusterfuzz

> because the ifunc code was breaking with all sorts of build options and obviously caused many problems with various sanitizers

for example, https://github.com/google/oss-fuzz/pull/10667

Have you tried Googles grpc fuzzer?

https://github.com/google/oss-fuzz/blob/master/projects/grpc...

https://www.fda.gov/medical-devices/digital-health-center-ex...

oss-fuzz: https://github.com/google/oss-fuzz :

> We support the libFuzzer, AFL++, and Honggfuzz fuzzing engines in combination with Sanitizers, as well as ClusterFuzz, a distributed fuzzer execution environment and reporting tool.

> Currently, OSS-Fuzz supports C/C++, Rust, Go, Python, Java/JVM, and JavaScript code. Other languages supported by LLVM may work too. OSS-Fuzz supports fuzzing x86_64 and i386 builds.

I love fuzzing as a technique and use it quite regularly, but running AFL++ on even a single program occupies all threads of a high end AMD server for weeks. I'm running it locally so only paying for the electricity. If it was a cloud instance it would cost a small fortune. I think this is a reason it is not used more widely.

I will note that Google have a programme for doing fuzz testing on open source projects using computer from their cloud: https://google.github.io/oss-fuzz/

Yes, mosh has fuzz tests in oss-fuzz [1].

[1] https://github.com/google/oss-fuzz/tree/master/projects/mosh

We will explore how Jazzer is used to automatically generate malicious inputs for Java programs, and how it compares to Symflower, which can automatically generate unit tests to uncover bugs and errors in your code. With the help of Jazzer, many bugs - some of them even in the OpenJDK - were found already. Also, as of March 2021, Jazzer is officially part of OSS-Fuzz, Google's cloud fuzzing engine. It should be noted that Jazzer is a pure "bug detection" utility that finds reproducers for errors in user code. Symflower can do the same, but provides additional functionalities to boost developer productivity, like generating high coverage unit tests and providing test templates for the software developer or tester.

https://github.com/google/clusterfuzz

At least Chromium has integrated multiple different fuzzers into their regular development workflow and found lots of bugs even before going public.

Then it is clear that the behavior of this for loop is either not important or not being tested. This could mean that the tests that you do have are not useful and can be deleted.

> For most non-trivial software the possible state-space is enormous and we generally don't/can't test all of it. So "not testing the (full) behaviour of your application is the default for any test strategy", if we could we wouldn't have bugs... Last I checked most software (including Google's) has plenty of bugs.

I have also used (setup, fixed findings) using https://google.github.io/clusterfuzz/ which uses coverage + properties to find bugs in the way C++ code handles pointers and other things.

> The next question would be let's say I spend my time writing the tests to resolve this (could be a lot of work) is that time better spent vs. other things I could be doing? (i.e. what's the ROI)

That is something that will depend largely on the team and the code you are on. If you are in experimental code that isn't in production, is there value to this? Likely not. If you are writing code that if it fails to parse some data correctly you'll have a huge headache trying to fix it? Likely yes.

The SRE workbook goes over making these calculations.

> Even ignoring that is there data to support that the quality of software where mutation testing was added improved measurably (e.g. less bugs files against the deployed product, better uptime, etc?)

I know that there are studies that show that tests reduce bugs but I do not know of studies that say that higher test coverage reduces bugs.

The goal of mutation testing isn't to drive up coverage though. It is to find out what cases are not being exercised and evaluating if they will cause a problem. For example mutation testing tools have picked up cases like this:

   if (debug) print("Got here!");