# DF-1817 - Source Verification

## Verdict: REPRODUCED (source-only confirmation)

**Finding**: sys/dev/drm/amd/powerplay/hwmgr/ppatomfwctrl.c:125-132

**Mechanism**: pp_atomfwctrl_get_voltage_table_v4 checks gpio_entry_num<=32 for destination but SOURCE voltage_gpio_lut[1] flexible array indexed by same count with no check against object_size. OOB read of BIOS data.

**Hardware dependency**: Requires AMD GPU with malicious VBIOS voltage LUT.

**Fix**: Add source LUT size validation before loop; cap iteration to min(dest, source).

## Verification method
Source-only confirmation. The cited code path was traced line-by-line in the
audited sys/ tree. The bug exists exactly as described. This is a HW-gated
driver finding — the vulnerable code path requires specific hardware (GPU,
controller, PHY, TPM, etc.) not present in the QEMU audit guest. Runtime
reproduction on this guest is not possible without the hardware.

## Fix validation
fix.diff authored and applied to guest source. All 40 fixes in this batch
compile cleanly in a single combined kernel build: `make -j6 nativekernel
KERNCONF=X86_64_GENERIC` → rc=0, zero -Werror violations.

**Kernel**: DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026