{
 "finding_id": "DF-3256",
 "status": "not_reproduced",
 "reproduced": 0,
 "impact": "none",
 "confidence": "certain",
 "verdict": "Race-mechanics-certain from source; live hit deliberately not attempted (statistical window between vfc_refcount++ at vfs_syscalls.c:359 and the read at procfs_vfsops.c:73, impact cosmetic - stale /proc entries only, all procfs ops re-resolve by pid). Two concurrent mounts can both observe refcount==2 and both skip at_exit(procfs_exit); the symmetric unmount gate is :109-110. Prior pack (untested) analysis re-confirmed this pass; fix registers the handler once (flag-guarded, never deregistered - procfs_exit is a no-op with no pfsnodes); compiled in the F40FIX build.",
 "exploit_chain": "",
 "evidence": "VERDICT.md with path:line citations; run.log where a live demo exists; fix.diff",
 "kernel_refs": [
  "sys/vfs/procfs/procfs_vfsops.c:73",
  "sys/vfs/procfs/procfs_vfsops.c:109",
  "sys/kern/vfs_syscalls.c:359"
 ],
 "poc_changes": "n/a - statistical race, cosmetic impact",
 "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": 30,
 "guest_dirty": 0,
 "build_cmd": "see build.sh",
 "run_cmd": "see run.sh",
 "code_hash": null,
 "notes": "",
 "recommended_fix": "register procfs_exit once via a registered flag; never deregister",
 "fix_status": "compile_validated",
 "fix_verdict": "fix.diff applied in the F40FIX verification kernel build (RC=0, zero -Werror errors); no runtime A/B for this item (line-certain hardening)"
}