IB/counters: Always initialize the port counter object

Port counter objects should be initialized even if alloc_stats is
unsupported, otherwise QP bind operations in user space can trigger a NULL
pointer deference if they try to bind QP on RDMA device which doesn't
support counters.

Fixes: f34a55e ("RDMA/core: Get sum value of all counters when perform a sysfs stat read")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Parav Pandit <[email protected]>
Reviewed-by: Mark Zhang <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

Author: paravmellanox

drivers/infiniband/core/counters.c

@@ -597,14 +597,17 @@ void rdma_counter_init(struct ib_device *dev)
 	struct rdma_port_counter *port_counter;
 	u32 port;
 
-	if (!dev->ops.alloc_hw_stats || !dev->port_data)
+	if (!dev->port_data)
 		return;
 
 	rdma_for_each_port(dev, port) {
 		port_counter = &dev->port_data[port].port_counter;
 		port_counter->mode.mode = RDMA_COUNTER_MODE_NONE;
 		mutex_init(&port_counter->lock);
 
+		if (!dev->ops.alloc_hw_stats)
+			continue;
+
 		port_counter->hstats = dev->ops.alloc_hw_stats(dev, port);
 		if (!port_counter->hstats)
 			goto fail;
@@ -627,9 +630,6 @@ void rdma_counter_release(struct ib_device *dev)
 	struct rdma_port_counter *port_counter;
 	u32 port;
 
-	if (!dev->ops.alloc_hw_stats)
-		return;
-
 	rdma_for_each_port(dev, port) {
 		port_counter = &dev->port_data[port].port_counter;
 		kfree(port_counter->hstats);