plugin/rewrite: copy msg before rewritting
Copy the msg to prevent messing with the (via the pointer) original
created message that may be stored in the cache or anything other data
store.
@@ -36,7 +36,10 @@ func NewResponseReverter(w dns.ResponseWriter, r *dns.Msg) *ResponseReverter {
}
// WriteMsg records the status code and calls the underlying ResponseWriter's WriteMsg method.
-func (r *ResponseReverter) WriteMsg(res *dns.Msg) error {
+func (r *ResponseReverter) WriteMsg(res1 *dns.Msg) error {
+ // Deep copy 'res' as to not (e.g). rewrite a message that's also stored in the cache.
+ res := res1.Copy()
+
res.Question[0] = r.originalQuestion
if r.ResponseRewrite {
for _, rr := range res.Answer {
