A use-after-free / double-free in c-ares' query-completion handling. The
same flaw — a query's callback being invoked while the query is still
linked in the channel's internal lookup structures — is present at
multiple points in the resend/finish path (timeout handling, response
handling, and query dispatch). If the query, or for `ares_getaddrinfo()`
the owning `host_query`, is freed as a side effect of that callback, it
is then accessed and/or freed a second time.