net: enetc: fix destroyed phylink dereference during unbind

[ Upstream commit 3af409ca27 ]

The following call path suggests that calling unregister_netdev on an
interface that is up will first bring it down.

enetc_pf_remove
-> unregister_netdev
   -> unregister_netdevice_queue
      -> unregister_netdevice_many
         -> dev_close_many
            -> __dev_close_many
               -> enetc_close
                  -> enetc_stop
                     -> phylink_stop

However, enetc first destroys the phylink instance, then calls
unregister_netdev. This is already dissimilar to the setup (and error
path teardown path) from enetc_pf_probe, but more than that, it is buggy
because it is invalid to call phylink_stop after phylink_destroy.

So let's first unregister the netdev (and let the .ndo_stop events
consume themselves), then destroy the phylink instance, then free the
netdev.

Fixes: 71b77a7a27 ("enetc: Migrate to PHYLINK and PCS_LYNX")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Vladimir Oltean 2021-02-16 12:16:28 +02:00 committed by Greg Kroah-Hartman
parent 79234cb9aa
commit 65a10cb163

View file

@ -1164,14 +1164,15 @@ static void enetc_pf_remove(struct pci_dev *pdev)
struct enetc_ndev_priv *priv;
priv = netdev_priv(si->ndev);
enetc_phylink_destroy(priv);
enetc_mdiobus_destroy(pf);
if (pf->num_vfs)
enetc_sriov_configure(pdev, 0);
unregister_netdev(si->ndev);
enetc_phylink_destroy(priv);
enetc_mdiobus_destroy(pf);
enetc_free_msix(priv);
enetc_free_si_resources(priv);