# DF-1816 - Source Verification

## Verdict: REPRODUCED (source-only confirmation)

**Finding**: sys/dev/drm/amd/powerplay/hwmgr/ppatomfwctrl.c:200

**Mechanism**: pp_atomfwctrl_lookup_gpio_pin advances offset by offsetof(gpio_id)+1=7 bytes but sizeof(atom_gpio_pin_assignment)=8. Loop drifts 1 byte/iter → OOB read.

**Hardware dependency**: Requires AMD GPU with VBIOS GPIO pin table. Every GPU calling this during hwmgr init.

**Fix**: Use sizeof(struct atom_gpio_pin_assignment) instead of offsetof+1.

## 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