net/rds: NULL pointer de-reference in rds_ib_add_one()

The parent field of a struct device may be NULL. The macro
ibdev_to_node() should check for that.

Signed-off-by: Ka-Cheong Poon <[e-mail]>
Acked-by: Santosh Shilimkar <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/rds/ib.h

···
 	int			*vector_load;
 };
 
-#define ibdev_to_node(ibdev) dev_to_node((ibdev)->dev.parent)
+static inline int ibdev_to_node(struct ib_device *ibdev)
+{
+	struct device *parent;
+
+	parent = ibdev->dev.parent;
+	return parent ? dev_to_node(parent) : NUMA_NO_NODE;
+}
 #define rdsibdev_to_node(rdsibdev) ibdev_to_node(rdsibdev->dev)
 
 /* bits for i_ack_flags */