Re: INFO: task hung in do_ip_vs_set_ctl (2)

[syzbot]

syzbot has found reproducer for the following crash on net-next commit
17dec0a949153d9ac00760ba2f5b78cb583e995f (Wed Apr 4 02:15:32 2018 +0000)
Merge branch 'userns-linus' of  
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
syzbot dashboard link:  
https://syzkaller.appspot.com/bug?extid=7810ed2e0cb359580c17

So far this crash happened 2 times on net-next, upstream.
C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5922062967242752
syzkaller reproducer:  
https://syzkaller.appspot.com/x/repro.syz?id=5359824032235520
Raw console output:  
https://syzkaller.appspot.com/x/log.txt?id=6352399027404800
Kernel config:  
https://syzkaller.appspot.com/x/.config?id=-2735707888269579554
compiler: gcc (GCC) 8.0.1 20180301 (experimental)

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7810ed2e0cb359580c17@xxxxxxxxxxxxxxxxxxxxxxxxx
It will help syzbot understand when the bug is fixed.

INFO: task syzkaller402106:4498 blocked for more than 120 seconds.
      Not tainted 4.16.0+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syzkaller402106 D22184  4498   4494 0x00000000
Call Trace:
 context_switch kernel/sched/core.c:2848 [inline]
 __schedule+0x807/0x1e40 kernel/sched/core.c:3490
 schedule+0xef/0x430 kernel/sched/core.c:3549
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3607
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0xe38/0x17f0 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x7d/0xd0 net/netfilter/nf_sockopt.c:115
 ip_setsockopt+0xd8/0xf0 net/ipv4/ip_sockglue.c:1253
 tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:2888
 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3039
 smc_setsockopt+0xc7/0x120 net/smc/af_smc.c:1289
 __sys_setsockopt+0x1bd/0x390 net/socket.c:1903
 SYSC_setsockopt net/socket.c:1914 [inline]
 SyS_setsockopt+0x34/0x50 net/socket.c:1911
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x445959
RSP: 002b:00007f2770618db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445959
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006dac20 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000140 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd81ae8f6f R14: 00007f27706199c0 R15: 0000000000000001

Showing all locks held in the system:
3 locks held by kworker/0:0/4:
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
__write_once_size include/linux/compiler.h:215 [inline]
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
atomic_long_set include/asm-generic/atomic-long.h:57 [inline]
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
set_work_data kernel/workqueue.c:617 [inline]
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 000000007346131c ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:  
process_one_work+0xaef/0x1b50 kernel/workqueue.c:2116
 #1: 00000000894403a3 ((addr_chk_work).work){+.+.}, at:  
process_one_work+0xb46/0x1b50 kernel/workqueue.c:2120
 #2: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
2 locks held by khungtaskd/877:
 #0: 00000000706bfe1c (rcu_read_lock){....}, at:  
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0: 00000000706bfe1c (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60  
kernel/hung_task.c:249
 #1: 00000000761e40d2 (tasklist_lock){.+.+}, at:  
debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470
2 locks held by getty/4464:
 #0: 00000000f90a9320 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000005dd151b8 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4465:
 #0: 00000000737b5b26 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 0000000017bb1ae5 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4466:
 #0: 00000000badd071e (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000a46de9fa (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4467:
 #0: 00000000112731eb (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000166cdec3 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4468:
 #0: 00000000d9915e26 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000abf02ab1 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4469:
 #0: 0000000041b9a2d2 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000003dbb7393 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4470:
 #0: 00000000dd811911 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000c9586a34 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
1 lock held by syzkaller402106/4498:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4517:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4523:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4535:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4537:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4548:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4553:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4564:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4571:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4581:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4588:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4598:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4603:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4615:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4620:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4631:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4511:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4514:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4526:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4530:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4542:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4546:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4558:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4562:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4574:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4578:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4590:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4594:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4606:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4610:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4622:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4626:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4501:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4518:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4522:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4533:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4539:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4550:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4556:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4567:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4572:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4582:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4586:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4597:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4602:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4612:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4617:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4628:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4506:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4515:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4527:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4531:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4543:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4547:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4559:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4563:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4575:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4579:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4591:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4595:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4607:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4611:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4623:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4627:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4503:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4519:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4524:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4534:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4538:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4549:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4554:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4566:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4569:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4580:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4585:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4596:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4601:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4613:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4619:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4630:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
2 locks held by syzkaller402106/4508:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
 #1: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x562/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syzkaller402106/4513:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4525:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4529:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4541:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4545:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4557:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4561:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4573:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4577:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4589:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4593:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4605:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4609:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4621:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4625:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4507:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4516:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4521:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4532:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4540:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4551:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4555:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4565:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4570:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4583:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4587:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4599:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4604:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4614:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4618:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4629:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4509:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4512:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4520:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4528:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4536:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4544:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4552:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4560:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4568:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4576:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4584:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4592:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4600:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4608:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syzkaller402106/4616:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74
1 lock held by syzkaller402106/4624:
 #0: 00000000bfa7d99e (ipvs->sync_mutex){+.+.}, at:  
do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by ipvs-b:0:0/4510:
 #0: 00000000ddc85278 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:74

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

NMI backtrace for cpu 1
CPU: 1 PID: 877 Comm: khungtaskd Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b9/0x29f lib/dump_stack.c:53
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0xc10/0xf60 kernel/hung_task.c:249
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:timekeeping_delta_to_ns kernel/time/timekeeping.c:351 [inline]
RIP: 0010:timekeeping_get_ns kernel/time/timekeeping.c:362 [inline]
RIP: 0010:ktime_get+0x308/0x430 kernel/time/timekeeping.c:764
RSP: 0018:ffff8801db007b98 EFLAGS: 00000002
RAX: 000000002930e468 RBX: 0000023e54000000 RCX: 0000000000000017
RDX: ffffed003b600f79 RSI: ffffffff8166cd99 RDI: 0000000000000004
RBP: ffff8801db007c90 R08: ffffffff88a752c0 R09: 0000000000000000
R10: ffffed0043fff001 R11: ffff88021fff8017 R12: dffffc0000000000
R13: 000000000006509e R14: ffff8801db007c68 R15: ffffffff88b172a0
FS:  0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000090e000 CR3: 00000001b130f000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 tick_nohz_irq_enter kernel/time/tick-sched.c:1124 [inline]
 tick_irq_enter+0xbc/0x3f0 kernel/time/tick-sched.c:1145
 irq_enter+0xb6/0xd0 kernel/softirq.c:346
 scheduler_ipi+0x39b/0xa30 kernel/sched/core.c:1768
 smp_reschedule_interrupt+0xed/0x660 arch/x86/kernel/smp.c:277
 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886
 </IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffffffff88a07c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffffffff1140f8a RCX: 0000000000000000
RDX: 1ffffffff1162e58 RSI: 0000000000000001 RDI: ffffffff88b172c0
RBP: ffffffff88a07c38 R08: ffffffff88a752c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff88a07cf0 R14: ffffffff88b172b0 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0xc2/0x440 arch/x86/kernel/process.c:354
 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:345
 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93
 cpuidle_idle_call kernel/sched/idle.c:151 [inline]
 do_idle+0x2f4/0x3c0 kernel/sched/idle.c:241
 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:346
 rest_init+0xe1/0xe4 init/main.c:437
 start_kernel+0x887/0x8ae init/main.c:717
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:443
 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:424
 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242
Code: ff ff 0f b6 8d 18 ff ff ff 48 ba 00 00 00 00 00 fc ff df 48 03 95 08  
ff ff ff 48 0f af d8 48 8b 85 10 ff ff ff 48 01 d8 48 d3 e8 <48> 03 85 20  
ff ff ff 48 c7 02 00 00 00 00 48 c7 42 08 00 00 00