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>

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index ca4c5dc..79b1602 100644 (file)
--- 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);