Q: Given the following code slice:
```
1 struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
2 				int newheadroom, int newtailroom,
3 				gfp_t gfp_mask)
4 {
5 	/*
6 	 *	Allocate the copy buffer
7 	 */
8 	struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom,
9 					gfp_mask, skb_alloc_rx_flag(skb),
10 					NUMA_NO_NODE);
11 	int oldheadroom = skb_headroom(skb);
12 	int head_copy_len, head_copy_off;
13 
14 	if (!n)
15 		return NULL;
16 
17 	skb_reserve(n, newheadroom);
18 
19 	/* Set the tail pointer and length */
20 	skb_put(n, skb->len);
21 
22 	head_copy_len = oldheadroom;
23 	head_copy_off = 0;
24 	if (newheadroom <= head_copy_len)
25 		head_copy_len = newheadroom;
26 	else
27 		head_copy_off = newheadroom - head_copy_len;
28 
29 	/* Copy the linear header and data. */
30 	BUG_ON(skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off,
31 			     skb->len + head_copy_len));
32 
33 	skb_copy_header(n, skb);
34 
35 	skb_headers_offset_update(n, newheadroom - oldheadroom);
36 
37 	return n;
38 }
```
which has a vulnerability among CWE-787 and among lines:
```
20 	skb_put(n, skb->len);
```
Please generate five possible patches for the vulnerability.