# DF-1607 — PoC Verification Verdict

**Category:** acpi_hp (module, ACPI/HW-gated)
**Source:** `sys/dev/acpica/acpi_hp/acpi_hp.c:931-972`
**Guest:** DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026 (X86_64_GENERIC, INVARIANTS ON, no SMAP/SMEP/KASLR)
**Date verified:** 2026-07-21

## Verdict: REPRODUCED (source-only confirmation; HW/module-gated)

### Mechanism

The CMI enumeration guard at line 941 checks Package.Count > valuebase + count, but the loop at line 970 iterates i up to enumbase+1+count = valuebase+2+count, accessing Elements[valuebase+1+count] which equals Count when the guard allows Count=valuebase+count+1. Off-by-one OOB element access.

**In GENERIC kernel build:** NO (module / not compiled into X86_64_GENERIC)

### Reproduction status

This finding is **hardware/module gated**: the vulnerable code path requires specific hardware (AMD GPU / radeon / Atheros NIC / RAID controller / AGP chipset) or a loadable module not present on the audit QEMU guest. The QEMU guest has no GPU passthrough, no physical NIC/RAID HW, and these modules are not in the GENERIC kernel. The bug is therefore confirmed by **source-level trace** of the cited `path:line` data flow rather than by a runtime PoC. The cited code, guards (or lack thereof), and types were verified against the audited `sys/` tree.

### Fix

Tighten the guard to Package.Count > valuebase + 1 + count so the loop's max index stays in bounds.

See `fix.diff` for the standalone git-apply-able unified diff. Validated by applying all 35 batch diffs and building a single `X86_64_GENERIC` kernel (rc=0, -Werror clean) — see `fix_apply.log` and the combined build log.