[PATCH 5.4 009/155] geneve: move debug check after netdev unregister

Greg Kroah-Hartman
2020-03-31T09:11:39Z

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 0fda7600c2e174fe27e9cf02e78e345226e441fa ]

The debug check must be done after unregister_netdevice_many() call --
the list_del() for this is done inside .ndo_stop.

Fixes: 2843a25348f8 ("geneve: speedup geneve tunnels dismantle")
Reported-and-tested-by: <syzbot+68a8ed58e3d17c700de5@syzkaller.appspotmail.com>
Cc: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/geneve.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -1845,8 +1845,6 @@ static void geneve_destroy_tunnels(struc
if (!net_eq(dev_net(geneve->dev), net))
unregister_netdevice_queue(geneve->dev, head);
}
-
- WARN_ON_ONCE(!list_empty(&gn->sock_list));
}

static void __net_exit geneve_exit_batch_net(struct list_head *net_list)
@@ -1861,6 +1859,12 @@ static void __net_exit geneve_exit_batch
/* unregister the devices gathered above */
unregister_netdevice_many(&list);
rtnl_unlock();
+
+ list_for_each_entry(net, net_list, exit_list) {
+ const struct geneve_net *gn = net_generic(net, geneve_net_id);
+
+ WARN_ON_ONCE(!list_empty(&gn->sock_list));
+ }
}

static struct pernet_operations geneve_net_ops = {