Q: Given the following code slice:
```
1 static int nfs_net_init(struct net *net)
3 	struct nfs_net *nn = net_generic(net, nfs_net_id);
6 	rpc_proc_register(net, &nn->rpcstats);```
which has a CWE-476 vulnerability at line:
```
6 	rpc_proc_register(net, &nn->rpcstats);
```
Please analyze the root cause of the vulnerability.