sctp: pass a kernel pointer to sctp_setsockopt_reset_assoc

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

@@ -4083,30 +4083,19 @@ static int sctp_setsockopt_reset_streams(struct sock *sk,
 	return sctp_send_reset_streams(asoc, params);
 }
 
-static int sctp_setsockopt_reset_assoc(struct sock *sk,
-				       char __user *optval,
+static int sctp_setsockopt_reset_assoc(struct sock *sk, sctp_assoc_t *associd,
 				       unsigned int optlen)
 {
 	struct sctp_association *asoc;
-	sctp_assoc_t associd;
-	int retval = -EINVAL;
-
-	if (optlen != sizeof(associd))
-		goto out;
 
-	if (copy_from_user(&associd, optval, optlen)) {
-		retval = -EFAULT;
-		goto out;
-	}
+	if (optlen != sizeof(*associd))
+		return -EINVAL;
 
-	asoc = sctp_id2assoc(sk, associd);
+	asoc = sctp_id2assoc(sk, *associd);
 	if (!asoc)
-		goto out;
-
-	retval = sctp_send_reset_assoc(asoc);
+		return -EINVAL;
 
-out:
-	return retval;
+	return sctp_send_reset_assoc(asoc);
 }
 
 static int sctp_setsockopt_add_streams(struct sock *sk,
@@ -4675,7 +4664,7 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 		retval = sctp_setsockopt_reset_streams(sk, kopt, optlen);
 		break;
 	case SCTP_RESET_ASSOC:
-		retval = sctp_setsockopt_reset_assoc(sk, optval, optlen);
+		retval = sctp_setsockopt_reset_assoc(sk, kopt, optlen);
 		break;
 	case SCTP_ADD_STREAMS:
 		retval = sctp_setsockopt_add_streams(sk, optval, optlen);