# DF-1690 — PoC Verification Verdict

**Category:** amdgpu powerplay (module, HW-gated)
**Source:** `sys/dev/drm/amd/powerplay/hwmgr/vega20_processpptables.c:714-721`
**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

append_vbios_pptable calls smu_atom_get_data_table(hwmgr->adev, index, NULL, NULL, NULL) at line 721 passing NULL as the size arg, discarding the table size. smu_atom_get_data_table returns bios+data_start with a 16-bit data_start not bounds-checked. Subsequent field reads (smc_dpm_table->maxvoltagestepgfx etc. lines 725+) assume the full struct atom_smc_dpm_info_v4_4 is present, but the table may be shorter -> OOB reads.

**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

Pass a real uint16_t table_size and assert table_size >= sizeof(struct atom_smc_dpm_info_v4_4) before field access.

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.