IB/mthca: check port validity in modify_qp

Modify_qp should check that the physical port number provided
is a legal value.

Signed-off-by: Jack Morgenstein <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/hw/mthca/mthca_qp.c

···
 		return -EINVAL;
 	}
 
+	if ((attr_mask & IB_QP_PORT) &&
+	    (attr->port_num == 0 || attr->port_num > dev->limits.num_ports)) {
+		mthca_dbg(dev, "Port number (%u) is invalid\n", attr->port_num);
+		return -EINVAL;
+	}
+
 	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
 	    attr->max_rd_atomic > dev->limits.max_qp_init_rdma) {
 		mthca_dbg(dev, "Max rdma_atomic as initiator %u too large (max is %d)\n",