Bug 249060 – Fix use-after-move in WebCore::SWClientConnection::postMessageToServiceWorkerClient()

• Component: Service Workers
• Status: RESOLVED FIXED

[David Kilzer (:ddkilzer)]

Fix use-after-move in WebCore::SWClientConnection::postMessageToServiceWorkerClient() from Source/WebCore/workers/service/SWClientConnection.cpp.

The `message` variable is involved in a use-after-move when `wasDispatched` returns `false` in the method below.

```
void SWClientConnection::postMessageToServiceWorkerClient(ScriptExecutionContextIdentifier destinationContextIdentifier, MessageWithMessagePorts&& message, ServiceWorkerData&& sourceData, String&& sourceOrigin)
{
    ASSERT(isMainThread());

    if (auto* destinationDocument = Document::allDocumentsMap().get(destinationContextIdentifier)) {
        postMessageToContainer(*destinationDocument, WTFMove(message), WTFMove(sourceData), WTFMove(sourceOrigin));
        return;
    }

    bool wasDispatched = ScriptExecutionContext::postTaskTo(destinationContextIdentifier, [message = WTFMove(message), sourceData = WTFMove(sourceData).isolatedCopy(), sourceOrigin = WTFMove(sourceOrigin).isolatedCopy()](auto& context) mutable {
        postMessageToContainer(context, WTFMove(message), WTFMove(sourceData), WTFMove(sourceOrigin));
    });
    if (wasDispatched)
        return;

    if (auto* sharedWorker = SharedWorkerThreadProxy::byIdentifier(destinationContextIdentifier)) {
        sharedWorker->thread().runLoop().postTask([message = WTFMove(message), sourceData = WTFMove(sourceData).isolatedCopy(), sourceOrigin = WTFMove(sourceOrigin).isolatedCopy()] (auto& context) mutable {
            postMessageToContainer(context, WTFMove(message), WTFMove(sourceData), WTFMove(sourceOrigin));
        });
    }
}
```

[Radar WebKit Bug Importer]

<rdar://problem/103202263>

[youenn fablet]

Pull request: https://github.com/WebKit/WebKit/pull/7473

[EWS]

Committed 257728@main (34ebbe87e188): <https://commits.webkit.org/257728@main>

Reviewed commits have been landed. Closing PR #7473 and removing active labels.