fix(websocket-websys): Unsubscribe from websocket events on drop

Avoid use-after-free handler invocation from JS side.

Fixes #5490

Pull-Request: #5521.

Cargo.toml

@@ -113,7 +113,7 @@ libp2p-webrtc = { version = "0.7.1-alpha", path = "transports/webrtc" }
 libp2p-webrtc-utils = { version = "0.2.1", path = "misc/webrtc-utils" }
 libp2p-webrtc-websys = { version = "0.3.0-alpha", path = "transports/webrtc-websys" }
 libp2p-websocket = { version = "0.43.2", path = "transports/websocket" }
-libp2p-websocket-websys = { version = "0.3.2", path = "transports/websocket-websys" }
+libp2p-websocket-websys = { version = "0.3.3", path = "transports/websocket-websys" }
 libp2p-webtransport-websys = { version = "0.3.0", path = "transports/webtransport-websys" }
 libp2p-yamux = { version = "0.45.2", path = "muxers/yamux" }
 multiaddr = "0.18.1"

transports/websocket-websys/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.3.3
+
+- Fix use-after-free handler invocation from JS side.
+  See [PR 5521](https://github.com/libp2p/rust-libp2p/pull/5521).
+
 ## 0.3.2
 
 - Change close code in drop implementation to `1000` given that in browsers only

transports/websocket-websys/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p-websocket-websys"
 edition = "2021"
 rust-version = "1.60.0"
 description = "WebSocket for libp2p under WASM environment"
-version = "0.3.2"
+version = "0.3.3"
 authors = ["Vince Vasta <vince.vasta@gmail.com>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

transports/websocket-websys/src/lib.rs

@@ -434,6 +434,12 @@ impl AsyncWrite for Connection {
 
 impl Drop for Connection {
     fn drop(&mut self) {
+        // Unset event listeners, as otherwise they will be called by JS after the handlers have already been dropped.
+        self.inner.socket.set_onclose(None);
+        self.inner.socket.set_onerror(None);
+        self.inner.socket.set_onopen(None);
+        self.inner.socket.set_onmessage(None);
+
         // In browsers, userland code is not allowed to use any other status code than 1000: https://websockets.spec.whatwg.org/#dom-websocket-close
         const REGULAR_CLOSE: u16 = 1000; // See https://www.rfc-editor.org/rfc/rfc6455.html#section-7.4.1.