fn test_json_attack()

in safetensors/src/tensor.rs [1307:1347]
36 lines of code
2 McCabe index (conditional complexity)

    fn test_json_attack() {
        let mut tensors = HashMap::new();
        let dtype = Dtype::F32;
        let shape = vec![2, 2];
        let data_offsets = (0, 16);
        for i in 0..10 {
            tensors.insert(
                format!("weight_{i}"),
                TensorInfo {
                    dtype,
                    shape: shape.clone(),
                    data_offsets,
                },
            );
        }

        let metadata = HashMetadata {
            metadata: None,
            tensors,
        };
        let serialized = serde_json::to_string(&metadata).unwrap();
        let serialized = serialized.as_bytes();

        let n = serialized.len();

        let filename = "out.safetensors";
        let mut f = std::io::BufWriter::new(std::fs::File::create(filename).unwrap());
        f.write_all(n.to_le_bytes().as_ref()).unwrap();
        f.write_all(serialized).unwrap();
        f.write_all(b"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0").unwrap();
        f.flush().unwrap();

        let reloaded = std::fs::read(filename).unwrap();
        match SafeTensors::deserialize(&reloaded) {
            Err(SafeTensorError::InvalidOffset(_)) => {
                // Yes we have the correct error, name of the tensor is random though
            }
            Err(err) => panic!("Unexpected error {err:?}"),
            Ok(_) => panic!("This should not be able to be deserialized"),
        }
    }