sctp: pass a kernel pointer to sctp_setsockopt_reset_streams

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

@@ -4061,12 +4061,10 @@ static int sctp_setsockopt_enable_strreset(struct sock *sk,
 }
 
 static int sctp_setsockopt_reset_streams(struct sock *sk,
-					 char __user *optval,
+					 struct sctp_reset_streams *params,
 					 unsigned int optlen)
 {
-	struct sctp_reset_streams *params;
 	struct sctp_association *asoc;
-	int retval = -EINVAL;
 
 	if (optlen < sizeof(*params))
 		return -EINVAL;
@@ -4074,23 +4072,15 @@ static int sctp_setsockopt_reset_streams(struct sock *sk,
 	optlen = min_t(unsigned int, optlen, USHRT_MAX +
 					     sizeof(__u16) * sizeof(*params));
 
-	params = memdup_user(optval, optlen);
-	if (IS_ERR(params))
-		return PTR_ERR(params);
-
 	if (params->srs_number_streams * sizeof(__u16) >
 	    optlen - sizeof(*params))
-		goto out;
+		return -EINVAL;
 
 	asoc = sctp_id2assoc(sk, params->srs_assoc_id);
 	if (!asoc)
-		goto out;
-
-	retval = sctp_send_reset_streams(asoc, params);
+		return -EINVAL;
 
-out:
-	kfree(params);
-	return retval;
+	return sctp_send_reset_streams(asoc, params);
 }
 
 static int sctp_setsockopt_reset_assoc(struct sock *sk,
@@ -4682,7 +4672,7 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 		retval = sctp_setsockopt_enable_strreset(sk, kopt, optlen);
 		break;
 	case SCTP_RESET_STREAMS:
-		retval = sctp_setsockopt_reset_streams(sk, optval, optlen);
+		retval = sctp_setsockopt_reset_streams(sk, kopt, optlen);
 		break;
 	case SCTP_RESET_ASSOC:
 		retval = sctp_setsockopt_reset_assoc(sk, optval, optlen);