Function libfuzzer_sys::fuzzer_mutate
source · [−]Expand description
The default libFuzzer
mutator.
You generally don’t have to use this at all unless you’re defining a
custom mutator with the fuzz_mutator!
macro.
Mutates data[..size]
in place such that the mutated data is no larger than
max_size
and returns the new size of the mutated data.
To only allow shrinking mutations, make max_size < size
.
To additionally allow mutations that grow the size of the data, make
max_size > size
.
Both size
and max_size
must be less than or equal to data.len()
.
Example
// Create some data in a buffer.
let mut data = vec![0; 128];
data[..b"hello".len()].copy_from_slice(b"hello");
// Ask `libFuzzer` to mutate the data. By setting `max_size` to our buffer's
// full length, we are allowing `libFuzzer` to perform mutations that grow
// the size of the data, such as insertions.
let size = b"hello".len();
let max_size = data.len();
let new_size = libfuzzer_sys::fuzzer_mutate(&mut data, size, max_size);
// Get the mutated data out of the buffer.
let mutated_data = &data[..new_size];