# DF-1624 — PoC Verification Verdict

**Category:** virtio_pci (IN GENERIC, virtio HW)
**Source:** `sys/dev/virtual/virtio/pci/virtio_pci.c:494-513`
**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

vtpci_intr_alloc MSI-X fallback path calls pci_release_msix_vector(dev, 0) at line 508 passing literal 0 as rid. The actual rid was stored at line 513 as sc->vtpci_intr_res[0].rid. pci_release_msix_vector_method (pci.c:1591) KASSERT(rid>0) -> INVARIANTS panic; or pci_find_msix_resource fails.

**In GENERIC kernel build:** YES

### 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 sc->vtpci_intr_res[0].rid (the stored rid) instead of literal 0.

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.