⬢ DragonFlyBSD Kernel Audit
DF-3618 / verdict.json
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{
  "finding_id": "DF-3618",
  "status": "inconclusive",
  "reproduced": 0,
  "impact": "none",
  "confidence": "speculative",
  "verdict": "ath_vap_delete (if_ath.c:1766-1884) disables interrupts at 1785 but never blocks or drains the driver taskqueue, unlike ath_reset (2889/3021) and ath_key_update_begin (3542) which block the same queue for exactly this class of hazard. ieee80211_vap_detach (1793) queues a disassoc frame after the first drain (acknowledged by the in-tree XXX Danger Will Robinson comment at 1796-1810); a concurrently-running/queued sc_txtask/sc_txqtask can be scheduling that frame sw-to-hw while the second ath_draintxq (1812) runs, and can hold buffers whose completion callbacks and mcastq linkage reference the avp that is kfreed at 1860. UAF-class window, speculative triggerability (SMP + TX load + vap destroy timing), admin-triggered entry. Not executable on the audit guest: no Atheros NIC (env.txt), and the race needs live hardware TX. Mitigation diff (taskqueue block+drain before kfree) applies clean.",
  "exploit_chain": "",
  "evidence": "README.md full trace with line cites; in-tree comment if_ath.c:1796-1810 acknowledging the race; env.txt (no ath hw); fix.diff git-apply clean",
  "kernel_refs": [
    "sys/dev/netif/ath/ath/if_ath.c:1785",
    "sys/dev/netif/ath/ath/if_ath.c:1793",
    "sys/dev/netif/ath/ath/if_ath.c:1812",
    "sys/dev/netif/ath/ath/if_ath.c:1860",
    "sys/dev/netif/ath/ath/if_ath.c:3542"
  ],
  "poc_changes": "n/a - no seeded PoC; analysis-only pack",
  "attempts": 1,
  "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": 30,
  "guest_dirty": 0,
  "build_cmd": "",
  "run_cmd": "",
  "code_hash": "",
  "notes": "Pass-2 lifetime analysis finding. Upstream reworked this path later; minimal mitigation provided. Low severity: admin-triggered entry, narrow window, panic-class outcome.",
  "recommended_fix": "taskqueue_block + taskqueue_drain of sc_txtask/sc_txqtask/sc_rxtask between the second ath_draintxq and kfree(avp), mirroring ath_resets discipline",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": 0,
  "fix_patched_reproduced": 0,
  "fix_verdict": "fix.diff (mitigation) applies clean via git apply --check; runtime validation impossible without ath hardware",
  "fix_evidence": "findings/poc/DF-3618/fix.diff"
}