RuntimeError: memory access out of bounds in WASM

I am currently building a small project that outsources it's processing into wasm compiled from rust. I am using wasm-bindgen, wasm-pack and webpack. Shortly after the WASM is instantiated, I get the error described above. When looking at the wat format, it tries to access memory f32.store offset=9331392 at ~9mb into the buffer. When I inserted console.log(wasm.memory.buffer.byteLength) into the glue code, it says that only 4mb is available. Does anyone know how I can either:

• make the memory grow dynamically
• set an initial memory size

Help would very much be appreciated. This is my first time using rust/wasm and I don't know how to increase the memory size here.

Edit:

Source code

lib.rs

use wasm_bindgen::{prelude::*, Clamped, JsCast};
use web_sys::ImageData;

extern crate wee_alloc;

#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;

#[allow(dead_code)]
fn main() {
    #[wasm_bindgen]
    pub struct Simulation {
        ...
    }

    #[wasm_bindgen]
    impl Simulation {
        #[wasm_bindgen(constructor)]
        pub fn new() -> Result<Simulation, JsValue> {
            ...
        }

        fn render(...) -> Result<(), JsValue> {
            ...
        }
    }
}