[wasmtime_wasi_http] `wasm trap: out of bounds memory access` on second function call

[Mr-1311]

I'm trying to make http request from a wasm component, in first request there is no issue but if I wanna call component again I'm getting wasm trap: out of bounds memory access error. I'm not sure if this is a bug or I'm doing something wrong.

for reproduce this is my host code:

use wasmtime::component::Val;
use wasmtime_wasi::{ResourceTable, WasiCtx, WasiCtxBuilder, WasiView};
use wasmtime_wasi_http::{WasiHttpCtx, WasiHttpView};

pub fn main() -> wasmtime::Result<()> {
    let engine = wasmtime::Engine::default();
    let bytes = std::fs::read("./components/js/test/test.wasm")?;
    let component = wasmtime::component::Component::new(&engine, bytes)?;

    let mut linker = wasmtime::component::Linker::<MyState>::new(&engine);
    wasmtime_wasi::add_to_linker_sync(&mut linker)?;
    wasmtime_wasi_http::add_only_http_to_linker_sync(&mut linker)?;

    let mut builder = WasiCtxBuilder::new();
    let mut store = wasmtime::Store::new(
        &engine,
        MyState {
            http: WasiHttpCtx::new(),
            ctx: builder.inherit_stdio().build(),
            table: ResourceTable::new(),
        },
    );

    let instance = linker.instantiate(&mut store, &component)?;
    let func = instance.get_func(&mut store, "testhttp").expect("testhttp export not found");

    let mut result = [Val::String("".to_string())];
    func.call(&mut store, &[Val::S32(10)], &mut result)?;
    func.post_return(&mut store)?;
    println!("testHttp result1: {:?}", result[0]);

    let mut result2 = [Val::String("".to_string())];
    func.call(&mut store, &[Val::S32(9)], &mut result2)?;
    func.post_return(&mut store)?;
    println!("testHttp result2: {:?}", result[0]);

    Ok(())
}

struct MyState {
    ctx: WasiCtx,
    http: WasiHttpCtx,
    table: ResourceTable,
}

impl WasiView for MyState {
    fn ctx(&mut self) -> &mut WasiCtx { &mut self.ctx }
    fn table(&mut self) -> &mut ResourceTable { &mut self.table }
}

impl WasiHttpView for MyState {
    fn ctx(&mut self) -> &mut WasiHttpCtx { &mut self.http }
    fn table(&mut self) -> &mut ResourceTable { &mut self.table }
}

this is my component:

export const testhttp = async (x) => {
  console.log(x);
  try {
    const response = await fetch("https://jsonplaceholder.typicode.com/todos/1");
    const data = await response.json();
    console.log("HTTP Response:", data);
    return JSON.stringify(data);
  } catch (error) {
    console.error("HTTP Request Error:", error);
    return error.toString();
  }
};

and wit file

package component:testhttp;

world test {
    export testhttp: func(x: s32) -> string;
}

I'm compiling js component with jco componentize test.js --wit wit/world.wit --world-name test --out test.wasm

and here is the stdout:

HTTP Response: { userId: 1, id: 1, title: "delectus aut autem", completed: false }
testHttp result1: String("{\"userId\":1,\"id\":1,\"title\":\"delectus aut autem\",\"completed\":false}")
HTTP Response: { userId: 1, id: 1, title: "delectus aut autem", completed: false }
Error: error while executing at wasm backtrace:
    0: 0x26facc - <unknown>!<wasm function 5415>
    1: 0x35b016 - <unknown>!<wasm function 7064>
    2: 0x25a4ae - <unknown>!<wasm function 5286>
    3: 0x24d192 - <unknown>!<wasm function 5251>
    4: 0x2470e8 - <unknown>!<wasm function 5249>
    5: 0x2557ab - <unknown>!<wasm function 5252>
    6: 0x256516 - <unknown>!<wasm function 5255>
    7: 0x382837 - <unknown>!<wasm function 7394>
    8: 0x2c3c91 - <unknown>!<wasm function 6095>
    9: 0x3438a3 - <unknown>!<wasm function 6970>
   10: 0x2558e5 - <unknown>!<wasm function 5252>
   11: 0x256516 - <unknown>!<wasm function 5255>
   12: 0x2d707e - <unknown>!<wasm function 6248>
   13: 0x313cba - <unknown>!<wasm function 6645>
   14: 0x222ec - <unknown>!<wasm function 88>
   15: 0x226549 - <unknown>!<wasm function 4979>
   16: 0x79cd2c - <unknown>!testhttp

Caused by:
    0: memory fault at wasm address 0x224e5af5 in linear memory of size 0x760000
    1: wasm trap: out of bounds memory access

[alexcrichton]

This might be a bug best opened against componentize-js? While there's certainly a possibility that it could be a bug in Wasmtime my gut reaction is that this is likely a bug in the wasm component itself created by componentize-js/jco, so I think it might be worthwhile to pursue that first.

[alexcrichton]

I'm going to close this as perhaps a bug in jco/componentize-js, as I don't think this is an issue with Wasmtime itself.