Invalid parameter type for custom fuzzilli corpus

[fuzzingfairy]

I'm getting

typeDecodingError("invalid parameter type") Skipping

when loading the below compiled program using the fuzzilli compiler and --importCorpusAll

function main() {
function foo(x) {
        return x;
}

for(i = 0; i < 1000; i++) {
        foo(i);
}
}
main();

[saelo]

The compiler is currently unmaintained and there have been a number of changes to Fuzzilli's IL so the compiler probably currently produces some invalid FuzzIL programs. Fuzzilli's IL is not yet stable, and we are also making changes to the IL specifically so that compilers have an easier job generating FuzzIL code. But it's not currently clear when we'll have a supported compiler, unfortunately...

[ghost]

Got it, Is there any way to generate a custom corpus right now?

[saelo]

No, sorry, there's no supported compiler at the moment. :( You could try hacking the existing one or this one though... In any case, the FuzzILTool might be useful when generating FuzzIL programs.

[rromanw]

Could you make estimate, how much work would it be for a person who is not very familiar with the code? And could you tell us, which was the last known good configuration for the compiler?

[saelo]

There's now a supported compiler in Fuzzilli: https://github.com/googleprojectzero/fuzzilli/commit/807625f0112df22bfe293aa4d36d67c31c4fb243 it's not yet feature complete but it should be fairly easy to extend.