Extend the Length Faster

If we run our binary with -help=1, LibFuzzer will helpfully inform us of all the different options to pass to the fuzzer to control its behavior.

./fuzzer.exe -help=1

The first thing we can adjust is the len_control option. Let's try setting it to 0, which will tell the fuzzer not to wait before extending the input to be very long.

./fuzzer.exe -len_control=0

Boop! That did it. In many cases, this is all you need to discover trivial buffer overflows.