# DF-1944 Verification

## Verdict
**SOURCE-CONFIRMED, INCONCLUSIVE-RUNTIME (HW/module gated).**

The cited defect exists in the audited source at `sys/dev/disk/nata/atapi-fd.c:168-258`. Reproduction
on the running guest is **not possible** because the affected code path is
gated behind hardware that is not present in the audit QEMU/KVM guest
(no AMD/i915 GPU, no LSI MegaRAID, no MMC/SDHCI controller, no FireWire, no
ATAPI floppy, etc.) and/or lives in a kernel module that is not loaded on the
GENERIC-running guest.

## Mechanism (source-only confirmation)
nata atapi-fd IS in GENERIC. Source: afd_reinit at L168-182 missing device: device_set_ivars(dev,NULL)+kfree(fdp)+return 1. Caller ata_reinit calls device_delete_child->afd_detach which short-circuits ENXIO at L140-141 because ivars NULL → disk_destroy skipped, cdev leaked. Later open of /dev/afd* derefs NULL si_drv1.

## Recommended fix
Before NULLing ivars, call disk_invalidate/disk_destroy/devstat_remove_entry so the cdev is torn down cleanly.

The full `git apply`-able diff lives in `fix.diff` in this folder; it was
applied as part of a single combined 41-finding kernel build that compiled
cleanly (rc=0, -Werror clean) — see `../fix_build_summary.txt`.

## Build validation
* `git apply --check` on this fix.diff: **OK**
* Combined kernel build (`X86_64_GENERIC`, INVARIANTS ON) with all 41
  findings' fix.diffs applied: **rc=0**, no warnings, no errors.
* The patched kernel was not booted/run because the affected code path
  requires hardware that the audit guest does not have.