[bug report] net/mlx5e: Handle FIB events to update tunnel endpoint device

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Vlad Buslov,

The patch 8914add2c9e5: "net/mlx5e: Handle FIB events to update
tunnel endpoint device" from Jan 25, 2021, leads to the following
static checker warning:

	drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:1639 mlx5e_tc_tun_init()
	error: passing non negative 1 to ERR_PTR

drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
  1622  struct mlx5e_tc_tun_encap *mlx5e_tc_tun_init(struct mlx5e_priv *priv)
  1623  {
  1624          struct mlx5e_tc_tun_encap *encap;
  1625          int err;
  1626  
  1627          encap = kvzalloc(sizeof(*encap), GFP_KERNEL);
  1628          if (!encap)
  1629                  return ERR_PTR(-ENOMEM);
  1630  
  1631          encap->priv = priv;
  1632          encap->fib_nb.notifier_call = mlx5e_tc_tun_fib_event;
  1633          spin_lock_init(&encap->route_lock);
  1634          hash_init(encap->route_tbl);
  1635          err = register_fib_notifier(dev_net(priv->netdev), &encap->fib_nb,
  1636                                      NULL, NULL);

register_fib_notifier() calls fib_net_dump() which eventually calls
fib6_walk_continue() which can return 1 if "walk is incomplete (i.e.
suspended)".

  1637          if (err) {
  1638                  kvfree(encap);
  1639                  return ERR_PTR(err);

If this returns 1 it will eventually lead to an Oops.

  1640          }
  1641  
  1642          return encap;
  1643  }

regards,
dan carpenter