[bug report] can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces

[bug report] can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces

[Dan Carpenter]

Hello Vincent Mailhol,

The patch 8537257874e9: "can: etas_es58x: add core support for ETAS
ES58X CAN USB interfaces" from Apr 10, 2021, leads to the following
Smatch static checker warning:

drivers/net/can/usb/etas_es58x/es58x_core.c:1818 es58x_open()
warn: inconsistent refcounting 'es58x_dev->opened_channel_cnt.counter':
  inc on: 1793
  dec on: 1818

drivers/net/can/usb/etas_es58x/es58x_core.c
    1785 static int es58x_open(struct net_device *netdev)
    1786 {
    1787         struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
    1788         int ret;
    1789 
    1790         if (atomic_inc_return(&es58x_dev->opened_channel_cnt) == 1) {
    1791                 ret = es58x_alloc_rx_urbs(es58x_dev);
    1792                 if (ret)
    1793                         return ret;
                                 ^^^^^^^^^^^
This error path should decrement &es58x_dev->opened_channel_cnt back to
zero?

    1794 
    1795                 ret = es58x_set_realtime_diff_ns(es58x_dev);
    1796                 if (ret)
    1797                         goto free_urbs;
    1798         }
    1799 
    1800         ret = open_candev(netdev);
    1801         if (ret)
    1802                 goto free_urbs;
    1803 
    1804         ret = es58x_dev->ops->enable_channel(es58x_priv(netdev));
    1805         if (ret)
    1806                 goto free_urbs;
    1807 
    1808         netif_start_queue(netdev);
    1809 
    1810         return ret;
    1811 
    1812  free_urbs:
    1813         if (atomic_dec_and_test(&es58x_dev->opened_channel_cnt))
    1814                 es58x_free_urbs(es58x_dev);
    1815         netdev_err(netdev, "%s: Could not open the network device: %pe\n",
    1816                    __func__, ERR_PTR(ret));
    1817 
--> 1818         return ret;
    1819 }

regards,
dan carpenter