{
 "finding_id": "DF-3391",
 "status": "reproduced",
 "reproduced": 1,
 "impact": "none",
 "confidence": "certain",
 "verdict": "Reproduced on the stock INVARIANTS guest (kldload ipfw3; note loading ipfw3 enables default-deny, so the probe runs detached and unloads the module). A NESTED opcode is required: setsockopt(IP_FW_X) with payload opcode IP_FW_X(49) re-enters ip_fw3_ctl_x, whose inner failure (invalid innermost opcode 0xBEEF -> EINVAL, kernel logs ip_fw3_ctl invalid option 48879) is DROPPED at ip_fw3.c:1058-1059 and setsockopt returns 0 - the firewall operator gets success for an operation that failed. Control case: flat invalid opcode through the glue propagates EINVAL correctly. First probe (flat opcode) hit the glue path and refuted nothing - the bug needs the nested dispatch; second probe reproduced. Post-fix A/B on the F40FIX-built ipfw3.ko: nested case returns -1/EINVAL.",
 "exploit_chain": "",
 "evidence": "VERDICT.md with path:line citations; run.log where a live demo exists; fix.diff",
 "kernel_refs": [
  "sys/net/ipfw3/ip_fw3.c:1058",
  "sys/net/ipfw3/ip_fw3.c:1059",
  "sys/netinet/raw_ip.c:334"
 ],
 "poc_changes": "initial probe used a flat invalid opcode (propagates correctly through the glue); fixed to a nested IP_FW_X payload opcode which is the only path that reaches the discarding case",
 "attempts": 2,
 "guest_uname": "DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026     root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64",
 "runtime_sec": 120,
 "guest_dirty": 0,
 "build_cmd": "see build.sh",
 "run_cmd": "see run.sh",
 "code_hash": "da85f711e7efead88aff13d7725c58bcb5f4ac92f029d104aae878df5067efb5",
 "notes": "",
 "recommended_fix": "error = ip_fw3_ctl_x(sopt) in the IP_FW_X case",
 "fix_status": "fixed",
 "fix_verdict": "A/B complete with the module rebuilt from the fixed tree: nested IP_FW_X opcode now returns -1/EINVAL (stock returned 0 while the kernel logged the inner EINVAL)."
}