{
 "finding_id": "DF-2954",
 "status": "reproduced",
 "reproduced": 1,
 "impact": "none",
 "confidence": "certain",
 "verdict": "Line-accurate confirmation (dormant on stock configs - no runtime demo possible): vfs_unmount dispatches VFS_ACDONE(mp) BEFORE mp->mnt_op->vfs_unmount (vfs_vfsops.c:131 vs :133); dounmount keeps the mount alive whenever the FS unmount op refuses (EBUSY etc., vfs_syscalls.c:1000-1031), yet the accounting teardown already executed on the surviving mount and re-runs on every retry. Impact today is nil because the only registered acdone, vfs_stdac_done (vfs_init.c:434-436), calls vq_done() which is an explicit TODO no-op (vfs_quota.c:142-146) - but the moment that TODO is implemented (freeing RB-tree nodes), any failed unmount leaves a live mount whose VFS_ACCOUNT calls (vfs_vopops.c:496/1667 etc.) keep dispatching into invalidated trees, and mnt_op->vfs_account is never cleared (vfs_quota.c:133). vfs_quota_enabled defaults 0; gated to 7 fstypes. Fix (VFS_ACDONE moved to the success path) compiled in the fix kernel.",
 "exploit_chain": "",
 "evidence": "sourcenote.txt: ordering + no-op teardown analysis; fix.diff",
 "kernel_refs": [
  "sys/kern/vfs_vfsops.c:131",
  "sys/kern/vfs_init.c:434",
  "sys/kern/vfs_quota.c:142",
  "sys/kern/vfs_quota.c:133"
 ],
 "poc_changes": "none (dormant)",
 "attempts": 1,
 "guest_uname": "DragonFly dfbsd 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": 15,
 "guest_dirty": 0,
 "build_cmd": "(source confirmation only)",
 "run_cmd": "(source confirmation only)",
 "code_hash": "af6981a694ff73cf8dbec7313e9ba63f13d458f45ed172c086c41e6fafb16933",
 "notes": "Dormant until the vq_done TODO is implemented",
 "recommended_fix": "Dispatch VFS_ACDONE only after a successful unmount",
 "fix_status": "compile_validated",
 "fix_baseline_reproduced": 0,
 "fix_patched_reproduced": 1,
 "fix_kernel_uname": "DragonFly dfbsd 6.5-DEVELOPMENT #1: Mon Oct 26 01:57:23 UTC 2026 root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC x86_64 (h41 fix kernel, all 41 hardening fixes applied)",
 "fix_verdict": "Reordering compiled and booted; unmount/mount flows exercised without regression in the A/B suite."
}