IPVS: Unknown mcast interface: í/./ò
IPVS: Unknown mcast interface: í/./ò
IPVS: Unknown mcast interface: í/./ò
IPVS: Unknown mcast interface: í/./ò
IPVS: Unknown mcast interface: í/./ò
INFO: task syzkaller115363:3920 blocked for more than 120 seconds.
      Not tainted 4.9.87-ga290494 #53
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syzkaller115363 D29520  3920   3918 0x00000000
 ffff8801d94de000 ffff8801d81daa00 ffff8801d3a84000 ffff8801d95e9800
 ffff8801db321b98 ffff8801d3577bc8 ffffffff838a5adb 0000000000000000
 0000000000000007 00ff8801d94de000 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a707f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a7a03>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3583
 [<ffffffff838ad012>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838ad012>] mutex_lock_nested+0x312/0x870 kernel/locking/mutex.c:621
 [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
 [<ffffffff8119de9f>] create_new_namespaces+0x37f/0x730 kernel/nsproxy.c:106
 [<ffffffff8119e82e>] unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:205
 [<ffffffff8113029d>] SYSC_unshare kernel/fork.c:2244 [inline]
 [<ffffffff8113029d>] SyS_unshare+0x3dd/0x6f0 kernel/fork.c:2194
 [<ffffffff81006504>] do_syscall_64+0x1a4/0x490 arch/x86/entry/common.c:282
 [<ffffffff838b6b53>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81373315>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81373315>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81238300>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3646:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d3edf>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3774:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b4d52>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200af14>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syzkaller115363/3920:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by syzkaller115363/3923:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by syzkaller115363/3924:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by syzkaller115363/3925:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by syzkaller115363/3927:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by syzkaller115363/3928:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f1fbe5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by init/3935:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open_by_driver drivers/tty/tty_io.c:2036 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2114
1 lock held by init/3936:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open_by_driver drivers/tty/tty_io.c:2036 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2114
1 lock held by init/3937:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open_by_driver drivers/tty/tty_io.c:2036 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2114
1 lock held by init/3938:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open_by_driver drivers/tty/tty_io.c:2036 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2114
1 lock held by init/3939:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open_by_driver drivers/tty/tty_io.c:2036 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2114
1 lock held by init/3940:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open_by_driver drivers/tty/tty_io.c:2036 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82004187>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2114

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.87-ga290494 #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8bf7d00 ffffffff81d95a19 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810bb230 ffff8801d8bf7d38
 ffffffff81da0b3d 0000000000000001 0000000000000000 ffff8801d94de418
Call Trace:
 [<ffffffff81d95a19>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d95a19>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da0b3d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0c77>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb324>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813738e0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813738e0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813738e0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813738e0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a92d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b6cec>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:374
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.9.87-ga290494 #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9abb000 task.stack: ffff8801d9af0000
RIP: 0010:[<ffffffff81dfce4a>] 
c [<ffffffff81dfce4a>] check_preemption_disabled+0xa/0x200 lib/smp_processor_id.c:12
RSP: 0018:ffff8801d9af7868  EFLAGS: 00000206
RAX: ffff8801d9abb000 RBX: ffffffff846501c0 RCX: ffffffff81dfd049
RDX: 0000000000000100 RSI: ffffffff83c18f80 RDI: ffffffff83c18fc0
RBP: ffff8801d9af7880 R08: ffffed003b35eec2 R09: ffff8801d9af7670
R10: 0000000000000008 R11: ffffed003b35eec1 R12: 0000000002080020
R13: 0000000000000140 R14: ffff8801b58d3280 R15: ffffffff82f0e485
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000018e43e0 CR3: 00000001d6a10000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000140
c ffff8801b58d3280
c ffffffff82f0e485
c ffff8801d9af7890
c
 ffffffff81dfd05c
c ffff8801d9af78b0
c ffffffff8128b2b5
c ffffffff82f0e485
c
 ffffffff846501c0
c ffff8801d9af78c8
c ffffffff8128796d
c 00000000000000e0
c
Call Trace:
 [<ffffffff81dfd05c>] debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:56
 [<ffffffff8128b2b5>] __rcu_is_watching kernel/rcu/tree.c:1053 [inline]
 [<ffffffff8128b2b5>] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:1067
 [<ffffffff8128796d>] rcu_read_lock_sched_held+0x8d/0x120 kernel/rcu/update.c:107
 [<ffffffff81539505>] trace_kmem_cache_alloc include/trace/events/kmem.h:53 [inline]
 [<ffffffff81539505>] kmem_cache_alloc+0x215/0x290 mm/slub.c:2730
 [<ffffffff82f0e485>] __build_skb+0x35/0x2d0 net/core/skbuff.c:310
 [<ffffffff82f0edf8>] __napi_alloc_skb+0x1e8/0x320 net/core/skbuff.c:512
 [<ffffffff8271d84d>] napi_alloc_skb include/linux/skbuff.h:2483 [inline]
 [<ffffffff8271d84d>] page_to_skb.isra.34+0x6d/0x6a0 drivers/net/virtio_net.c:274
 [<ffffffff82724954>] receive_mergeable drivers/net/virtio_net.c:378 [inline]
 [<ffffffff82724954>] receive_buf drivers/net/virtio_net.c:477 [inline]
 [<ffffffff82724954>] virtnet_receive+0x844/0x1cf0 drivers/net/virtio_net.c:723
 [<ffffffff82725e26>] virtnet_poll+0x26/0x140 drivers/net/virtio_net.c:741
 [<ffffffff82f46b06>] napi_poll net/core/dev.c:5219 [inline]
 [<ffffffff82f46b06>] net_rx_action+0x396/0xe00 net/core/dev.c:5284
 [<ffffffff838bd616>] __do_softirq+0x206/0x951 kernel/softirq.c:284
 [<ffffffff81146b2e>] run_ksoftirqd+0x2e/0x60 kernel/softirq.c:676
 [<ffffffff811a5d61>] smpboot_thread_fn+0x5c1/0x8f0 kernel/smpboot.c:163
 [<ffffffff8119a92d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b6cec>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:374
Code: 
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c<49> 
c89 
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c