{
 "finding_id": "DF-2656",
 "status": "reproduced",
 "reproduced": 1,
 "impact": null,
 "confidence": "certain",
 "verdict": "source-confirmed (no runtime PoC; deterministic code trace of the cited path:line in the read-only sys/ tree). Code-certain divergence + invariant analysis: with the shipped guards, compressed output is independent of stale heap contents (the subtle invariant holds today); M_ZERO on the six allocations restores upstream calloc semantics as defense-in-depth so a future refactor of the high_water logic cannot turn stale kernel heap into compressed-file bytes. Compile-validated with the batch build.",
 "exploit_chain": "no escalation path (Info-tier hardening; see VERDICT.md)",
 "evidence": "VERDICT.md mechanism/verdict sections; fix.diff",
 "kernel_refs": [
  "sys/vfs/hammer2/zlib/hammer2_zlib_deflate.c:239",
  "sys/vfs/hammer2/zlib/hammer2_zlib_deflate.c:254",
  "sys/vfs/hammer2/zlib/hammer2_zlib_deflate.c:915"
 ],
 "poc_changes": "none (source-only confirmation for this Info-tier item)",
 "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": 0,
 "guest_dirty": 0,
 "build_cmd": "n/a (source-only confirmation)",
 "run_cmd": "n/a",
 "code_hash": "cc79527d77d277f7c24af69b72129ecf6620b5fa59462ff814632781b5d0f724",
 "notes": "Status semantics: source-confirmed rows follow the established Info-tier batch convention (deterministic code trace of the cited path:line); HW-gated rows are not_reproduced because the required device is absent on this QEMU guest.",
 "recommended_fix": "Add M_ZERO to the six kmallocs (matches upstream zcalloc/calloc allocation semantics).",
 "fix_status": "not_testable",
 "fix_kernel_uname": null,
 "fix_baseline_reproduced": null,
 "fix_patched_reproduced": null,
 "fix_verdict": "fix.diff compile-validated in the batch combined kernel build (all 37 diffs of this batch applied to in-guest /usr/src; make -j6 nativekernel KERNCONF=X86_64_GENERIC, see batch build log referenced in VERDICT.md); no behavior A/B performed for this Info-tier item; behavior A/B intentionally skipped for Info tier",
 "fix_evidence": "batch combined kernel build log (see findings/poc/_batch41 note in VERDICT.md)"
}