# DF-4713 — amdgpu_irq.c: unchecked optional-callback calls in dispatch/update

**File:** `sys/dev/drm/amd/amdgpu/amdgpu_irq.c` (pass 2, GLM 5.3)
**Severity:** Low · **Confidence:** likely (missing check certain; trigger
config/hardware-gated)

## Build / Run

Hardware-gated (requires an AMD GPU for the amdgpu IRQ machinery to run; the
audit QEMU guest has only virtio-gpu — verified, see env.txt). No runtime PoC
per the DF-4519/DF-2201 HW-gated protocol. The fix is **compile-validated**
against the patched `amdgpu_irq.c` inside the full amdgpu KLD module build
(`-Werror`):

```sh
# guest (root):
cd /usr/src && patch -p1 < /tmp/df4713_fix.diff
cd /usr/src/sys/dev/drm/amd/amdgpu && make    # MOD_BUILD_RC=0 (build.log)
```

## What to look at

* `VERDICT.md` — full narrative incl. the DF-4643 lock-type verification and
  all killed candidates (fini double-free, get/put races, registry bounds).
* `build.log` — full untrimmed amdgpu module build log (`MOD_BUILD_RC=0`).
* `fix.diff` — NULL guards for `funcs->process` (dispatch) and `funcs->set`
  (update), matching the file's own existing guard style.
* `env.txt` — guest uname, no-AMD-GPU proof, shim citations.