# DF-0273 PoC — SIOCSIFDESCR fall-through to SIOCSIFFLAGS

## Build
```
cc -o descr_fallthrough descr_fallthrough.c
```

## Run (as root — SIOCSIFDESCR requires RESTRICTEDROOT)
```
./descr_fallthrough
```

## Expected (bug present)
```
[*] lo0 flags BEFORE SIOCSIFDESCR:
  flags=...<UP,RUNNING,MULTICAST,...>
[*] lo0 flags AFTER SIOCSIFDESCR(len=2):
  flags=...<RUNNING,MULTICAST,...>      <-- IFF_UP CLEARED
[!] DF-0273 REPRODUCED: IFF_UP cleared by setting a description
```

## Expected (fixed)
Flags unchanged after SIOCSIFDESCR — the `break;` prevents fall-through.