Neon provides functionality for creating JavaScript ArrayBuffer
(and the Buffer
subtype) instances backed by bytes allocated outside of V8/Node. The JsArrayBuffer::external
and JsBuffer::external
did not require T: 'static
prior to Neon 0.10.1
. This allowed creating an externally backed buffer from types that may be freed while they are still referenced by a JavaScript ArrayBuffer
.
The following example demonstrates use after free. It compiles on versions <0.10.1
and fails to compile afterward.
pub fn soundness_hole(mut cx: FunctionContext) -> JsResult<JsArrayBuffer> {
let mut data = vec![0u8, 1, 2, 3];
// Creating an external from `&mut [u8]` instead of `Vec<u8>` since there is a blanket impl
// of `AsMut<T> for &mut T`
let buf = JsArrayBuffer::external(&mut cx, data.as_mut_slice());
// `buf` is still holding a reference to `data`!
drop(data);
Ok(buf)
}
{ "license": "CC0-1.0" }