RDMA/cma: Check for NULL conn_param in rdma_accept

Check that conn_param is not null before dereferencing it when
processing rdma_accept().  This is necessary to prevent a possible
system crash, which can be caused by user space.

Problem found by code inspection.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 23 insertions, 15 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index ca4c5dcd7133..79b16028e898 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2616,14 +2616,16 @@ static int cma_connect_iw(struct rdma_id_private *id_priv,
         if (ret)
                 goto out;
 
-        iw_param.ord = conn_param->initiator_depth;
-        iw_param.ird = conn_param->responder_resources;
-        iw_param.private_data = conn_param->private_data;
-        iw_param.private_data_len = conn_param->private_data_len;
-        if (id_priv->id.qp)
+        if (conn_param) {
+                iw_param.ord = conn_param->initiator_depth;
+                iw_param.ird = conn_param->responder_resources;
+                iw_param.private_data = conn_param->private_data;
+                iw_param.private_data_len = conn_param->private_data_len;
+                iw_param.qpn = id_priv->id.qp ? id_priv->qp_num : conn_param->qp_num;
+        } else {
+                memset(&iw_param, 0, sizeof iw_param);
                 iw_param.qpn = id_priv->qp_num;
-        else
-                iw_param.qpn = conn_param->qp_num;
+        }
         ret = iw_cm_connect(cm_id, &iw_param);
 out:
         if (ret) {
@@ -2765,14 +2767,20 @@ int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
 
         switch (rdma_node_get_transport(id->device->node_type)) {
         case RDMA_TRANSPORT_IB:
-                if (id->qp_type == IB_QPT_UD)
-                        ret = cma_send_sidr_rep(id_priv, IB_SIDR_SUCCESS,
-                                                conn_param->private_data,
-                                                conn_param->private_data_len);
-                else if (conn_param)
-                        ret = cma_accept_ib(id_priv, conn_param);
-                else
-                        ret = cma_rep_recv(id_priv);
+                if (id->qp_type == IB_QPT_UD) {
+                        if (conn_param)
+                                ret = cma_send_sidr_rep(id_priv, IB_SIDR_SUCCESS,
+                                                        conn_param->private_data,
+                                                        conn_param->private_data_len);
+                        else
+                                ret = cma_send_sidr_rep(id_priv, IB_SIDR_SUCCESS,
+                                                        NULL, 0);
+                } else {
+                        if (conn_param)
+                                ret = cma_accept_ib(id_priv, conn_param);
+                        else
+                                ret = cma_rep_recv(id_priv);
+                }
                 break;
         case RDMA_TRANSPORT_IWARP:
                 ret = cma_accept_iw(id_priv, conn_param);