# VERDICT — DF-3745

**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
radeon_get_atom_connector_info_from_object_table() (the DCE4+ connector path) dereferences a web of unvalidated BIOS values: (1) table bases from u16 offsets usStateArrayOffset/usClockInfoArrayOffset/usNonClockInfoArrayOffset/usDisplayPathTableOffset/usConnectorObjectTableOffset/usEncoderObjectTableOffset/usRouterObjectTableOffset (:537-548); (2) the display-path walk accumulates attacker u16 usSize values (:551-557) — two 0x8000 sizes put the record pointer 64 KiB out; (3) per-object usRecordOffset/usSrcDstTableOffset u16 offsets dereferenced immediately (:654-656, :685-698); (4) router src/dst: enum_id runs to *num_dst_objs (u8<=255) then indexes ucMuxState[enum_id] though ucMuxState is UCHAR[2] (atombios.h:4380-4395) — up to 253 B OOB (:732/:740); (5) record chains stepped by ucRecordSize with no image-end bound (:660-672, :772-803). All of this reads past the rdev->bios heap image at boot/attach (values feed connector config; distinct surface from the power-table indices of DF-1200). Harness on guest demonstrates each sub-case. 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_objtable.c).

## Harness result
Command: ./run.sh (after ./build.sh)
Expected/observed: path walk goes OOB at path 1 (offset 0x6666 > 4096-byte image); record offset 0xFFF0 deref; enum_id=255 vs ucMuxState[2]; chain walks past image end; exit_code=0
Full logs: build.log, run.log.

## Impact / exploit chain
crafted Object_Header table -> OOB pointer arithmetic at radeon_modeset_init -> reads of adjacent kernel heap -> crash (values also propagate into connector/encoder setup)

## Fix
validate every BIOS offset/size against the image length before use (needs the bios_size plumbing of DF-3744) — fix.diff.

## Honest notes
- DF-3745 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.