# DF-1193 — ciss CISS_BIG_MAP_BUS divide-by-zero (build/run scripts)

This finding is hardware-gated (HP Smart Array PCI controller). The guest has
no such controller, so the bug cannot be triggered at runtime on this host.
Source-level trace + a single-fix kernel build are the validation evidence.

## Files
- `VERDICT.md`  — detailed source-level analysis
- `fix.diff`    — git-apply-able patch adding `drives_per_scsi_bus==0` guard
- `env.txt`     — guest environment snapshot
- `fix_build.log` — kernel-build output (cumulative batch, all 5 findings)

## build.sh
```sh
#!/bin/sh
# No userspace PoC to build -- the bug is in the ciss driver attach path.
# Validate the fix.diff by building the kernel after applying it.
echo 'build.sh: no userspace PoC for DF-1193 (hardware-gated driver bug).'
echo 'To validate the fix, apply fix.diff and build a kernel:'
echo '  cd /usr/src && patch -p1 < fix.diff && make -j6 nativekernel KERNCONF=X86_64_GENERIC'
```

## run.sh
```sh
#!/bin/sh
# Cannot be triggered on a guest without an HP Smart Array controller.
echo 'run.sh: DF-1193 is hardware-gated (HP Smart Array ciss).'
echo 'No HP controller is present on this guest (pciconf -l shows only i440FX/virtio).'
echo 'See VERDICT.md for the source-level confirmation.'
```