sctp: pass a kernel pointer to sctp_setsockopt_pr_supported

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

@@ -3925,24 +3925,20 @@ static int sctp_setsockopt_recvnxtinfo(struct sock *sk, int *val,
 }
 
 static int sctp_setsockopt_pr_supported(struct sock *sk,
-					char __user *optval,
+					struct sctp_assoc_value *params,
 					unsigned int optlen)
 {
-	struct sctp_assoc_value params;
 	struct sctp_association *asoc;
 
-	if (optlen != sizeof(params))
+	if (optlen != sizeof(*params))
 		return -EINVAL;
 
-	if (copy_from_user(&params, optval, optlen))
-		return -EFAULT;
-
-	asoc = sctp_id2assoc(sk, params.assoc_id);
-	if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
+	asoc = sctp_id2assoc(sk, params->assoc_id);
+	if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
 	    sctp_style(sk, UDP))
 		return -EINVAL;
 
-	sctp_sk(sk)->ep->prsctp_enable = !!params.assoc_value;
+	sctp_sk(sk)->ep->prsctp_enable = !!params->assoc_value;
 
 	return 0;
 }
@@ -4691,7 +4687,7 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 		retval = sctp_setsockopt_recvnxtinfo(sk, kopt, optlen);
 		break;
 	case SCTP_PR_SUPPORTED:
-		retval = sctp_setsockopt_pr_supported(sk, optval, optlen);
+		retval = sctp_setsockopt_pr_supported(sk, kopt, optlen);
 		break;
 	case SCTP_DEFAULT_PRINFO:
 		retval = sctp_setsockopt_default_prinfo(sk, optval, optlen);