vxlan: move debug check after netdev unregister

The debug check must be done after unregister_netdevice_many() call -- the hlist_del_rcu() for this is done inside .ndo_stop. This is the same with commit 0fda760 ("geneve: move debug check after netdev unregister") Test commands: ip netns del A ip netns add A ip netns add B ip netns exec B ip link add vxlan0 type vxlan vni 100 local 10.0.0.1 \ remote 10.0.0.2 dstport 4789 srcport 4789 4789 ip netns exec B ip link set vxlan0 netns A ip netns exec A ip link set vxlan0 up ip netns del B Splat looks like: [ 73.176249][ T7] ------------[ cut here ]------------ [ 73.178662][ T7] WARNING: CPU: 4 PID: 7 at drivers/net/vxlan.c:4743 vxlan_exit_batch_net+0x52e/0x720 [vxlan] [ 73.182597][ T7] Modules linked in: vxlan openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 mlx5_core nfp mlxfw ixgbevf tls sch_fq_codel nf_tables nfnetlink ip_tables x_tables unix [ 73.190113][ T7] CPU: 4 PID: 7 Comm: kworker/u16:0 Not tainted 5.11.0-rc7+ #838 [ 73.193037][ T7] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 73.196986][ T7] Workqueue: netns cleanup_net [ 73.198946][ T7] RIP: 0010:vxlan_exit_batch_net+0x52e/0x720 [vxlan] [ 73.201509][ T7] Code: 00 01 00 00 0f 84 39 fd ff ff 48 89 ca 48 c1 ea 03 80 3c 1a 00 0f 85 a6 00 00 00 89 c2 48 83 c2 02 49 8b 14 d4 48 85 d2 74 ce <0f> 0b eb ca e8 b9 51 db dd 84 c0 0f 85 4a fe ff ff 48 c7 c2 80 bc [ 73.208813][ T7] RSP: 0018:ffff888100907c10 EFLAGS: 00010286 [ 73.211027][ T7] RAX: 000000000000003c RBX: dffffc0000000000 RCX: ffff88800ec411f0 [ 73.213702][ T7] RDX: ffff88800a278000 RSI: ffff88800fc78c70 RDI: ffff88800fc78070 [ 73.216169][ T7] RBP: ffff88800b5cbdc0 R08: fffffbfff424de61 R09: fffffbfff424de61 [ 73.218463][ T7] R10: ffffffffa126f307 R11: fffffbfff424de60 R12: ffff88800ec41000 [ 73.220794][ T7] R13: ffff888100907d08 R14: ffff888100907c50 R15: ffff88800fc78c40 [ 73.223337][ T7] FS: 0000000000000000(0000) GS:ffff888114800000(0000) knlGS:0000000000000000 [ 73.225814][ T7] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 73.227616][ T7] CR2: 0000562b5cb4f4d0 CR3: 0000000105fbe001 CR4: 00000000003706e0 [ 73.229700][ T7] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 73.231820][ T7] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 73.233844][ T7] Call Trace: [ 73.234698][ T7] ? vxlan_err_lookup+0x3c0/0x3c0 [vxlan] [ 73.235962][ T7] ? ops_exit_list.isra.11+0x93/0x140 [ 73.237134][ T7] cleanup_net+0x45e/0x8a0 [ ... ] Fixes: 57b6112 ("vxlan: speedup vxlan tunnels dismantle") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Link: https://lore.kernel.org/r/20210221154552.11749-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mariux64 · Feb 23, 2021 · 92584dd · 92584dd
1 parent 2c8396d
commit 92584dd
Showing 1 changed file with 8 additions and 3 deletions.
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
@@ -4721,7 +4721,6 @@ static void vxlan_destroy_tunnels(struct net *net, struct list_head *head)
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
 	struct vxlan_dev *vxlan, *next;
 	struct net_device *dev, *aux;
-	unsigned int h;
 
 	for_each_netdev_safe(net, dev, aux)
 		if (dev->rtnl_link_ops == &vxlan_link_ops)
@@ -4735,14 +4734,13 @@ static void vxlan_destroy_tunnels(struct net *net, struct list_head *head)
 			unregister_netdevice_queue(vxlan->dev, head);
 	}
 
-	for (h = 0; h < PORT_HASH_SIZE; ++h)
-		WARN_ON_ONCE(!hlist_empty(&vn->sock_list[h]));
 }
 
 static void __net_exit vxlan_exit_batch_net(struct list_head *net_list)
 {
 	struct net *net;
 	LIST_HEAD(list);
+	unsigned int h;
 
 	rtnl_lock();
 	list_for_each_entry(net, net_list, exit_list) {
@@ -4755,6 +4753,13 @@ static void __net_exit vxlan_exit_batch_net(struct list_head *net_list)
 
 	unregister_netdevice_many(&list);
 	rtnl_unlock();
+
+	list_for_each_entry(net, net_list, exit_list) {
+		struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+
+		for (h = 0; h < PORT_HASH_SIZE; ++h)
+			WARN_ON_ONCE(!hlist_empty(&vn->sock_list[h]));
+	}
 }
 
 static struct pernet_operations vxlan_net_ops = {