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Date:   Wed, 15 Aug 2018 13:28:02 -0700
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Message-ID: <000000000000c5b63005737f290d@google.com>
Subject: Re: unregister_netdevice: waiting for DEV to become free (2)
From:   syzbot <syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com>
To:     linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
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Sender: linux-kernel-owner@vger.kernel.org
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syzbot has found a reproducer for the following crash on:

HEAD commit:    31130a16d459 Merge tag 'for-linus-4.19-rc1-tag' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1116b46c400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e8d52931cda051de
dashboard link: https://syzkaller.appspot.com/bug?extid=30209ea299c09d8785c9
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=11617322400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
unregister_netdevice: waiting for lo to become free. Usage count = 1
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
IPVS: stopping master sync thread 6855 ...
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: stopping master sync thread 6859 ...
IPVS: ftp: loaded support on port[0] = 21
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
bond0: Enslaving bond_slave_0 as an active interface with an up link
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
IPVS: stopping master sync thread 7118 ...
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: stopping master sync thread 7122 ...
IPVS: ftp: loaded support on port[0] = 21
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
bond0: Enslaving bond_slave_0 as an active interface with an up link
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
IPVS: stopping master sync thread 7381 ...
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: stopping master sync thread 7385 ...
IPVS: ftp: loaded support on port[0] = 21
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
bond0: Enslaving bond_slave_0 as an active interface with an up link
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
IPVS: stopping master sync thread 7644 ...
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: sync thread started: state = MASTER, mcast_ifn = syz_tun, syncid = 0,  
id = 0
IPVS: stopping master sync thread 7648 ...
IPVS: ftp: loaded support on port[0] = 21
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
bond0: Enslaving bond_slave_0 as an active interface with an up link
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready