diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 98237feb607a..e1965d9cbcf8 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -517,9 +517,10 @@ static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
 	return tot_pages;
 }
 
-int rds_rdma_extra_size(struct rds_rdma_args *args)
+int rds_rdma_extra_size(struct rds_rdma_args *args,
+			struct rds_iov_vector *iov)
 {
-	struct rds_iovec vec;
+	struct rds_iovec *vec;
 	struct rds_iovec __user *local_vec;
 	int tot_pages = 0;
 	unsigned int nr_pages;
@@ -530,13 +531,23 @@ int rds_rdma_extra_size(struct rds_rdma_args *args)
 	if (args->nr_local == 0)
 		return -EINVAL;
 
+	iov->iov = kcalloc(args->nr_local,
+			   sizeof(struct rds_iovec),
+			   GFP_KERNEL);
+	if (!iov->iov)
+		return -ENOMEM;
+
+	vec = &iov->iov[0];
+
+	if (copy_from_user(vec, local_vec, args->nr_local *
+			   sizeof(struct rds_iovec)))
+		return -EFAULT;
+	iov->len = args->nr_local;
+
 	/* figure out the number of pages in the vector */
-	for (i = 0; i < args->nr_local; i++) {
-		if (copy_from_user(&vec, &local_vec[i],
-				   sizeof(struct rds_iovec)))
-			return -EFAULT;
+	for (i = 0; i < args->nr_local; i++, vec++) {
 
-		nr_pages = rds_pages_in_vec(&vec);
+		nr_pages = rds_pages_in_vec(vec);
 		if (nr_pages == 0)
 			return -EINVAL;
 
@@ -558,15 +569,15 @@ int rds_rdma_extra_size(struct rds_rdma_args *args)
  * Extract all arguments and set up the rdma_op
  */
 int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
-			  struct cmsghdr *cmsg)
+		       struct cmsghdr *cmsg,
+		       struct rds_iov_vector *vec)
 {
 	struct rds_rdma_args *args;
 	struct rm_rdma_op *op = &rm->rdma;
 	int nr_pages;
 	unsigned int nr_bytes;
 	struct page **pages = NULL;
-	struct rds_iovec iovstack[UIO_FASTIOV], *iovs = iovstack;
-	int iov_size;
+	struct rds_iovec *iovs;
 	unsigned int i, j;
 	int ret = 0;
 
@@ -586,31 +597,23 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 		goto out_ret;
 	}
 
-	/* Check whether to allocate the iovec area */
-	iov_size = args->nr_local * sizeof(struct rds_iovec);
-	if (args->nr_local > UIO_FASTIOV) {
-		iovs = sock_kmalloc(rds_rs_to_sk(rs), iov_size, GFP_KERNEL);
-		if (!iovs) {
-			ret = -ENOMEM;
-			goto out_ret;
-		}
+	if (vec->len != args->nr_local) {
+		ret = -EINVAL;
+		goto out_ret;
 	}
 
-	if (copy_from_user(iovs, (struct rds_iovec __user *)(unsigned long) args->local_vec_addr, iov_size)) {
-		ret = -EFAULT;
-		goto out;
-	}
+	iovs = vec->iov;
 
 	nr_pages = rds_rdma_pages(iovs, args->nr_local);
 	if (nr_pages < 0) {
 		ret = -EINVAL;
-		goto out;
+		goto out_ret;
 	}
 
 	pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
 	if (!pages) {
 		ret = -ENOMEM;
-		goto out;
+		goto out_ret;
 	}
 
 	op->op_write = !!(args->flags & RDS_RDMA_READWRITE);
@@ -623,7 +626,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 	op->op_sg = rds_message_alloc_sgs(rm, nr_pages);
 	if (!op->op_sg) {
 		ret = -ENOMEM;
-		goto out;
+		goto out_pages;
 	}
 
 	if (op->op_notify || op->op_recverr) {
@@ -635,7 +638,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 		op->op_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL);
 		if (!op->op_notifier) {
 			ret = -ENOMEM;
-			goto out;
+			goto out_pages;
 		}
 		op->op_notifier->n_user_token = args->user_token;
 		op->op_notifier->n_status = RDS_RDMA_SUCCESS;
@@ -681,7 +684,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 		 */
 		ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write);
 		if (ret < 0)
-			goto out;
+			goto out_pages;
 		else
 			ret = 0;
 
@@ -714,13 +717,11 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 				nr_bytes,
 				(unsigned int) args->remote_vec.bytes);
 		ret = -EINVAL;
-		goto out;
+		goto out_pages;
 	}
 	op->op_bytes = nr_bytes;
 
-out:
-	if (iovs != iovstack)
-		sock_kfree_s(rds_rs_to_sk(rs), iovs, iov_size);
+out_pages:
 	kfree(pages);
 out_ret:
 	if (ret)
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 6bfaf05b63b2..4d2523100093 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -386,6 +386,18 @@ static inline void rds_message_zcopy_queue_init(struct rds_msg_zcopy_queue *q)
 	INIT_LIST_HEAD(&q->zcookie_head);
 }
 
+struct rds_iov_vector {
+	struct rds_iovec *iov;
+	int               len;
+};
+
+struct rds_iov_vector_arr {
+	struct rds_iov_vector *vec;
+	int                    len;
+	int                    indx;
+	int                    incr;
+};
+
 struct rds_message {
 	refcount_t		m_refcount;
 	struct list_head	m_sock_item;
@@ -904,13 +916,13 @@ int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen);
 int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen);
 int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen);
 void rds_rdma_drop_keys(struct rds_sock *rs);
-int rds_rdma_extra_size(struct rds_rdma_args *args);
-int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
-			  struct cmsghdr *cmsg);
+int rds_rdma_extra_size(struct rds_rdma_args *args,
+			struct rds_iov_vector *iov);
 int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
 			  struct cmsghdr *cmsg);
 int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
-			  struct cmsghdr *cmsg);
+			  struct cmsghdr *cmsg,
+			  struct rds_iov_vector *vec);
 int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
 			  struct cmsghdr *cmsg);
 void rds_rdma_free_op(struct rm_rdma_op *ro);
diff --git a/net/rds/send.c b/net/rds/send.c
index fe785ee819dd..ec2267cbf85f 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -876,13 +876,15 @@ static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
  * rds_message is getting to be quite complicated, and we'd like to allocate
  * it all in one go. This figures out how big it needs to be up front.
  */
-static int rds_rm_size(struct msghdr *msg, int num_sgs)
+static int rds_rm_size(struct msghdr *msg, int num_sgs,
+		       struct rds_iov_vector_arr *vct)
 {
 	struct cmsghdr *cmsg;
 	int size = 0;
 	int cmsg_groups = 0;
 	int retval;
 	bool zcopy_cookie = false;
+	struct rds_iov_vector *iov, *tmp_iov;
 
 	for_each_cmsghdr(cmsg, msg) {
 		if (!CMSG_OK(msg, cmsg))
@@ -893,8 +895,24 @@ static int rds_rm_size(struct msghdr *msg, int num_sgs)
 
 		switch (cmsg->cmsg_type) {
 		case RDS_CMSG_RDMA_ARGS:
+			if (vct->indx >= vct->len) {
+				vct->len += vct->incr;
+				tmp_iov =
+					krealloc(vct->vec,
+						 vct->len *
+						 sizeof(struct rds_iov_vector),
+						 GFP_KERNEL);
+				if (!tmp_iov) {
+					vct->len -= vct->incr;
+					return -ENOMEM;
+				}
+				vct->vec = tmp_iov;
+			}
+			iov = &vct->vec[vct->indx];
+			memset(iov, 0, sizeof(struct rds_iov_vector));
+			vct->indx++;
 			cmsg_groups |= 1;
-			retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
+			retval = rds_rdma_extra_size(CMSG_DATA(cmsg), iov);
 			if (retval < 0)
 				return retval;
 			size += retval;
@@ -951,10 +969,11 @@ static int rds_cmsg_zcopy(struct rds_sock *rs, struct rds_message *rm,
 }
 
 static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
-			 struct msghdr *msg, int *allocated_mr)
+			 struct msghdr *msg, int *allocated_mr,
+			 struct rds_iov_vector_arr *vct)
 {
 	struct cmsghdr *cmsg;
-	int ret = 0;
+	int ret = 0, ind = 0;
 
 	for_each_cmsghdr(cmsg, msg) {
 		if (!CMSG_OK(msg, cmsg))
@@ -968,7 +987,10 @@ static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
 		 */
 		switch (cmsg->cmsg_type) {
 		case RDS_CMSG_RDMA_ARGS:
-			ret = rds_cmsg_rdma_args(rs, rm, cmsg);
+			if (ind >= vct->indx)
+				return -ENOMEM;
+			ret = rds_cmsg_rdma_args(rs, rm, cmsg, &vct->vec[ind]);
+			ind++;
 			break;
 
 		case RDS_CMSG_RDMA_DEST:
@@ -1084,6 +1106,11 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 		      sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY));
 	int num_sgs = ceil(payload_len, PAGE_SIZE);
 	int namelen;
+	struct rds_iov_vector_arr vct = {0};
+	int ind;
+
+	/* expect 1 RDMA CMSG per rds_sendmsg. can still grow if more needed. */
+	vct.incr = 1;
 
 	/* Mirror Linux UDP mirror of BSD error message compatibility */
 	/* XXX: Perhaps MSG_MORE someday */
@@ -1220,7 +1247,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 		num_sgs = iov_iter_npages(&msg->msg_iter, INT_MAX);
 	}
 	/* size of rm including all sgs */
-	ret = rds_rm_size(msg, num_sgs);
+	ret = rds_rm_size(msg, num_sgs, &vct);
 	if (ret < 0)
 		goto out;
 
@@ -1270,7 +1297,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 	rm->m_conn_path = cpath;
 
 	/* Parse any control messages the user may have included. */
-	ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
+	ret = rds_cmsg_send(rs, rm, msg, &allocated_mr, &vct);
 	if (ret) {
 		/* Trigger connection so that its ready for the next retry */
 		if (ret ==  -EAGAIN)
@@ -1348,9 +1375,18 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 	if (ret)
 		goto out;
 	rds_message_put(rm);
+
+	for (ind = 0; ind < vct.indx; ind++)
+		kfree(vct.vec[ind].iov);
+	kfree(vct.vec);
+
 	return payload_len;
 
 out:
+	for (ind = 0; ind < vct.indx; ind++)
+		kfree(vct.vec[ind].iov);
+	kfree(vct.vec);
+
 	/* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
 	 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
 	 * or in any other way, we need to destroy the MR again */
