{
  "equivalence_summary": "The timeout alternate trigger and the parent duplicate-QID TCP trigger share the same core lifetime error: c-ares invoked query completion callbacks while the completing query remained linked/discoverable in channel lookup structures, allowing callback reentrancy to find/free the same query before the outer completion path freed it.",
  "same_root_cause": true,
  "same_sink": "query callback invoked before detach/free in src/lib/ares_process.c",
  "parent_path": {
    "entrypoint": "ares_getaddrinfo() over TCP DNS",
    "trigger": "malicious TCP peer sends FORMERR without OPT, duplicate same-QID NXDOMAIN, follow-on query, then TCP reset",
    "sink": "read_answers() deferred REQUEUE_ENDQUERY flush invokes query->callback before ares_free_query()",
    "observed_impact": "code_execution marker through reclaimed host_query"
  },
  "variant_path": {
    "entrypoint": "ares_query_dnsrec() over UDP DNS",
    "trigger": "DNS peer receives query and withholds response to drive process_timeouts(); callback reenters with public ares_cancel()",
    "sink": "pre-fix process_timeouts() calls ares_requeue_query(..., requeue=NULL), reaching end_query() callback-before-free while query remains discoverable",
    "observed_impact": "vulnerable-only double free detected by glibc MALLOC_CHECK_=3"
  },
  "fix_equivalence": "v1.34.7 covers both paths by routing deferred ENDQUERY, timeout, and send retry/end handling through ares_flush_requeue(), which detaches queries before invoking callbacks and drains retries iteratively.",
  "confidence": "high"
}