# VERDICT — DF-3746

**Status**: inconclusive (source-certain; harness-reproduced arithmetic; kernel path unreachable on this guest)
**reproduced**: 0 (in-kernel) — harness demonstration: YES
**Impact on real hardware**: Medium — CWE-125 Out-of-bounds Read

## Finding
The voltage-object family reads past the VBIOS image on self-declared data: (1) atom_lookup_voltage_object_v1/v2/v3 (:3382-3431) walk bounded only by the table's own usStructureSize (u16) — size=0xFFF8 walks ~16k objects over a 64-byte table and past the image (harness: 16290 OOB reads); returned OOB objects are then dereferenced by radeon_atom_get_max/min_voltage, get_voltage_step, get_svi2_info. (2) v1 advance bug: offset += offsetof(...)+ucNumOfVoltageEntries BYTES while entries are VOLTAGE_LUT_ENTRY=4 bytes (:3393-3394) — v2 correctly multiplies by sizeof (:3410-3411) — so v1 mis-parses every subsequent object. (3) radeon_atom_get_leakage_vddc_based_on_leakage_params checks only size<sizeof(header) (:3237) then indexes vddc_buf[j*ucElbVDDC_Num+i] with two BIOS u8 counts — up to element 65024 (~130 KB past the array base, far past any VBIOS image). Kernel path unreachable on this guest.

## Why not reproduced in-kernel
The QEMU guest is virtio-only (no AMD GPU): `pciconf -l` shows no 1002 device;
`kldstat` shows radeon not loaded. `/boot/kernel/radeon.ko` exists (the vulnerable code ships in
the default install) but cannot attach, so radeon_atombios.c parse paths never execute here.
All conclusions are source-level (path:line above) plus the on-guest harness (harness_voltobj.c).

## Harness result
Command: ./run.sh (after ./build.sh)
Expected/observed: v1 walk with self-declared size 0xFFF8 over a 64-byte table: 16290 reads past image end; stride bug: 7 vs 16 bytes for 3 entries; leakage index 64769 -> 129538 B past array; exit_code=0
Full logs: build.log, run.log.

## Impact / exploit chain
crafted VoltageObjectInfo/ASIC_ProfilingInfo tables -> OOB heap reads at DPM init -> wrong voltage objects used (mis-programmed voltages) and/or crash

## Fix
bound walks by the image length (bios_size plumbing) and fix the v1 stride — fix.diff.

## Honest notes
- DF-3746 does NOT re-report pass-1 findings DF-1198/1199/1200 (power-table state_index mismatch,
  asic_ss_info underflow, power-table indices) — different functions/tables/fields.
- fix validation not possible on this guest (no hardware); fix.diff is source-authored only.

## Fix status (batch validation)
Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest `make -j6 nativekernel KERNCONF=X86_64_GENERIC` completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.