sctp: pass a kernel pointer to sctp_setsockopt_recvnxtinfo

Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/socket.c

@@ -3913,18 +3913,13 @@ static int sctp_setsockopt_recvrcvinfo(struct sock *sk, int *val,
 	return 0;
 }
 
-static int sctp_setsockopt_recvnxtinfo(struct sock *sk,
-				       char __user *optval,
+static int sctp_setsockopt_recvnxtinfo(struct sock *sk, int *val,
 				       unsigned int optlen)
 {
-	int val;
-
 	if (optlen < sizeof(int))
 		return -EINVAL;
-	if (get_user(val, (int __user *) optval))
-		return -EFAULT;
 
-	sctp_sk(sk)->recvnxtinfo = (val == 0) ? 0 : 1;
+	sctp_sk(sk)->recvnxtinfo = (*val == 0) ? 0 : 1;
 
 	return 0;
 }
@@ -4693,7 +4688,7 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 		retval = sctp_setsockopt_recvrcvinfo(sk, kopt, optlen);
 		break;
 	case SCTP_RECVNXTINFO:
-		retval = sctp_setsockopt_recvnxtinfo(sk, optval, optlen);
+		retval = sctp_setsockopt_recvnxtinfo(sk, kopt, optlen);
 		break;
 	case SCTP_PR_SUPPORTED:
 		retval = sctp_setsockopt_pr_supported(sk, optval, optlen);