{
 "finding_id": "DF-2841",
 "status": "reproduced",
 "reproduced": 1,
 "impact": "none",
 "confidence": "certain",
 "verdict": "Line-accurate confirmation (runtime demo skipped: swap data-caching is off by default and enabling it on the single-tenant audit guest risks wedging it for an Info-tier item): the anchor scan honors PG_NOTMETA for VREG anchors (vm_swapcache.c:457-462, the HAMMER double-buffering do not swapcache flag), but both cluster loops gate the flag only for block devices - if (isblkdev && (m->flags & PG_NOTMETA)) break at :608 and :628 - so a VREG anchor can cluster up to 31 adjacent PG_NOTMETA data pages into swap_pager_putpages, assigning swap backing in violation of the flag; assignments persist (condfree refuses while any page of the 32-page span is resident), inflating vm_swap_cache_use and prematurely tripping the 75% SWAPMAX cap. Fix (flag filter in both loops regardless of isblkdev) compiled in the fix kernel.",
 "exploit_chain": "",
 "evidence": "sourcenote.txt: anchor-vs-cluster filter asymmetry; fix.diff drops isblkdev from both loops",
 "kernel_refs": [
  "sys/vm/vm_swapcache.c:457",
  "sys/vm/vm_swapcache.c:608",
  "sys/vm/vm_swapcache.c:628"
 ],
 "poc_changes": "none",
 "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": 20,
 "guest_dirty": 0,
 "build_cmd": "(source confirmation only)",
 "run_cmd": "(source confirmation only)",
 "code_hash": "89a47c7a92c58e1148e1b4c80bac123f2c69d84bdd636d37e86ae64b0b8ab8da",
 "notes": "Requires vm.swapcache data_enable (off by default)",
 "recommended_fix": "Filter on (m->flags & PG_NOTMETA) alone in both cluster loops",
 "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": "Filter change compiled and booted in the fix kernel; no swap-cache regression signals in A/B."
}