# DF-1923 Verification

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

The cited defect exists in the audited source at `sys/dev/disk/sdhci/sdhci_pci.c:350-436`. 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)
sdhci IS in GENERIC but no SDHCI HW in guest. Source: sdhci_pci_attach loop assigns sc->mem_res[i] for every iteration but only increments sc->num_slots on success. Partial failure: mem_res[k]=NULL or allocated-but-orphaned (num_slots not advanced). sdhci_pci_detach then iterates `for(i=0; i<num_slots; i++)` indexing mem_res[i] which can be NULL → bus_release_resource(NULL) crashes.

## Recommended fix
Iterate `for(i=0; i<6; i++)` and skip NULL mem_res[], matching attach's BAR-slot indexing.

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.