Re: [PATCH v3 net-next 00/23] net: add preliminary netdev refcount tracking
flat view
From: Andrew Lunn <andrew@lunn.ch>
Date: 2021-12-06 23:24:08
On Sat, Dec 04, 2021 at 08:21:54PM -0800, Eric Dumazet wrote:
From: Eric Dumazet <redacted> Two first patches add a generic infrastructure, that will be used to get tracking of refcount increments/decrements.
Hi Eric Using this i found: [ 774.108901] unregister_netdevice: waiting for eth0 to become free. Usage count = 4 [ 774.110864] leaked reference. [ 774.110874] dst_alloc+0x7a/0x180 [ 774.110887] ip6_dst_alloc+0x27/0x90 [ 774.110894] ip6_pol_route+0x257/0x430 [ 774.110900] ip6_pol_route_output+0x19/0x20 [ 774.110905] fib6_rule_lookup+0x18b/0x270 [ 774.110914] ip6_route_output_flags_noref+0xaa/0x110 [ 774.110918] ip6_route_output_flags+0x32/0xa0 [ 774.110922] ip6_dst_lookup_tail.constprop.0+0x181/0x240 [ 774.110929] ip6_dst_lookup_flow+0x43/0xa0 [ 774.110934] inet6_csk_route_socket+0x166/0x200 [ 774.110943] inet6_csk_xmit+0x56/0x130 [ 774.110946] __tcp_transmit_skb+0x53b/0xc30 [ 774.110953] __tcp_send_ack.part.0+0xc6/0x1a0 [ 774.110958] tcp_send_ack+0x1c/0x20 [ 774.110964] __tcp_ack_snd_check+0x42/0x200 [ 774.110968] tcp_rcv_established+0x27a/0x6f0 [ 774.110973] leaked reference. [ 774.110975] ipv6_add_dev+0x13e/0x4f0 [ 774.110982] addrconf_notify+0x2ca/0x950 [ 774.110989] raw_notifier_call_chain+0x49/0x60 [ 774.111000] call_netdevice_notifiers_info+0x50/0x90 [ 774.111007] __dev_change_net_namespace+0x30d/0x6c0 [ 774.111016] do_setlink+0xdc/0x10b0 [ 774.111024] __rtnl_newlink+0x608/0xa10 [ 774.111031] rtnl_newlink+0x49/0x70 [ 774.111038] rtnetlink_rcv_msg+0x14f/0x380 [ 774.111046] netlink_rcv_skb+0x55/0x100 [ 774.111053] rtnetlink_rcv+0x15/0x20 [ 774.111059] netlink_unicast+0x230/0x340 [ 774.111064] netlink_sendmsg+0x252/0x4b0 [ 774.111075] sock_sendmsg+0x65/0x70 [ 774.111080] ____sys_sendmsg+0x24e/0x290 [ 774.111084] ___sys_sendmsg+0x81/0xc0 I'm using GNS3 to simulate a network topology. So a collection of veth pairs, bridges and tap interfaces spread over a few namespaces. The network being simulated uses Segment Routing. And traceroute might also involved in this somehow. I have 3 patches applied, to make traceroute actually work when SRv6 is being used. You can find v3 here: https://lore.kernel.org/netdev/20211203162926.3680281-3-andrew@lunn.ch/T/ (local) I'm not sure if these patches are part of the problem or not. None of the traces i've seen are directly on the ICMP path. traceroute is using udp, and one of the traces above is for tcp, and the other looks like it is moving an interface into a different namespace? This is net-next from today. Any ideas? Thanks Andrew