{
 "finding_id": "DF-3121",
 "status": "not_reproduced",
 "reproduced": 0,
 "impact": "none",
 "confidence": "certain",
 "verdict": "Line-accurate confirmation; no runtime demonstration attempted (requires persistent quota-file I/O failure). ufs_dqsync clears DQ_MOD|DQ_LOCK|DQ_WANT unconditionally after VOP_WRITE (ufs_quota.c:935) even when the write failed or short-wrote, and ufs_dqrele discards the return (:886-887) before inserting the dquot on the free list - the in-core usage update is lost forever with no retry path. UFS quotas are compiled out of the stock kernel (ufs_vfsops.c:77 #ifndef QUOTA -> EOPNOTSUPP, confirmed live: quotactl Q_QUOTAON returns EOPNOTSUPP as root); the F40FIX verification kernel enables options QUOTA so the fixed ufs_quota.c compiles against real consumers. Fix keeps DQ_MOD on failure.",
 "exploit_chain": "",
 "evidence": "VERDICT.md with path:line citations; run.log where a live demo exists; fix.diff",
 "kernel_refs": [
  "sys/vfs/ufs/ufs_quota.c:935",
  "sys/vfs/ufs/ufs_quota.c:886"
 ],
 "poc_changes": "n/a; stock kernel lacks options QUOTA (EOPNOTSUPP live-confirmed)",
 "attempts": 0,
 "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": 10,
 "guest_dirty": 0,
 "build_cmd": "see build.sh",
 "run_cmd": "see run.sh",
 "code_hash": null,
 "notes": "",
 "recommended_fix": "clear DQ_MOD only when the quota-file write succeeded",
 "fix_status": "compile_validated",
 "fix_verdict": "compiled in the QUOTA-enabled F40FIX kernel where the quota machinery runs live (Q_QUOTAON + Q_SETQUOTA exercised during the DF-3243 A/B, exercising the fixed dqsync path on success); the failure branch (persistent I/O error) not simulated."
}