Q: Given the following code slice:
```
1 static int xdp_do_generic_redirect_map(struct net_device *dev,
2 				       struct sk_buff *skb,
3 				       struct xdp_buff *xdp,
4 				       struct bpf_prog *xdp_prog,
5 				       void *fwd,
6 				       enum bpf_map_type map_type, u32 map_id)
7 {
8 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
9 	struct bpf_map *map;
10 	int err;
11 
12 	switch (map_type) {
13 	case BPF_MAP_TYPE_DEVMAP:
14 		fallthrough;
15 	case BPF_MAP_TYPE_DEVMAP_HASH:
16 		map = READ_ONCE(ri->map);
17 		if (unlikely(map)) {
18 			WRITE_ONCE(ri->map, NULL);
19 			err = dev_map_redirect_multi(dev, skb, xdp_prog, map,
20 						     ri->flags & BPF_F_EXCLUDE_INGRESS);
21 		} else {
22 			err = dev_map_generic_redirect(fwd, skb, xdp_prog);
23 		}
24 		if (unlikely(err))
25 			goto err;
26 		break;
27 	case BPF_MAP_TYPE_XSKMAP:
28 		err = xsk_generic_rcv(fwd, xdp);
29 		if (err)
30 			goto err;
31 		consume_skb(skb);
32 		break;
33 	case BPF_MAP_TYPE_CPUMAP:
34 		err = cpu_map_generic_redirect(fwd, skb);
35 		if (unlikely(err))
36 			goto err;
37 		break;
38 	default:
39 		err = -EBADRQC;
40 		goto err;
41 	}
42 
43 	_trace_xdp_redirect_map(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index);
44 	return 0;
45 err:
46 	_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index, err);
47 	return err;
48 }
```
which has a vulnerability among CWE-476 and among lines:
```
4 				       struct bpf_prog *xdp_prog,
```
Please generate five possible patches for the vulnerability.