CVE-2025-59351: DragonFly vulnerable to panics due to nil pointer dereference when using variables created alongside an error

We found two instances in the DragonFly codebase where the first return value of a function is dereferenced even when the function returns an error (figures 9.1 and 9.2). This can result in a nil dereference, and cause code to panic. The codebase may contain additional instances of the bug.

request, err := source.NewRequestWithContext(ctx, parentReq.Url,
parentReq.UrlMeta.Header)
if err != nil {
log.Errorf("generate url [%v] request error: %v", request.URL, err)
span.RecordError(err)
return err
}

Eve is a malicious actor operating a peer machine. She sends a dfdaemonv1.DownRequest request to her peer Alice. Alice’s machine receives the request, resolves a nil variable in the server.Download method, and panics.