313617 pages reserved
lowmemorykiller: Killing 'syz-executor.3' (20976) (tgid 20964), adj 1000,
   to free 35240kB on behalf of 'kworker/u4:2' (18259) because
   cache 7520kB is below limit 8192kB for oom_score_adj 1
   Free memory is -13312kB above reserved
INFO: task kworker/1:0:18 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:0     D26792    18      2 0x80000000
Workqueue: ipv6_addrconf addrconf_verify_work
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
 ffff8801da6f4740 ffff8801d4bdee00 ffff8801d0e49b80 ffff8801d3aa17c0
 ffff8801db721018 ffff8801da717ae8 ffffffff828075c2 0000000000000002
 ffff8801da6f4ff0 ffffed003b4de9fd 00ff8801da6f4740 ffff8801db7218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828094a3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff8280b51d>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8280b51d>] mutex_lock_nested+0x38d/0x900 kernel/locking/mutex.c:621
 [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff826c31be>] addrconf_verify_work+0xe/0x20 net/ipv6/addrconf.c:4364
 [<ffffffff81131001>] process_one_work+0x831/0x15f0 kernel/workqueue.c:2092
 [<ffffffff81131e96>] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
3 locks held by kworker/1:0/18:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/1896:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2023:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor.4/10668:
 #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff81520d73>] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369
1 lock held by syz-executor.4/10758:
 #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff81520d73>] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #1
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000001 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4df89>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4df1c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810984b4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131c65d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c65d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c65d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c65d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 18259 Comm: kworker/u4:2 Not tainted 4.9.141+ #1
Workqueue: netns cleanup_net
c
task: ffff8801ca442f80 task.stack: ffff8801d5c08000
RIP: 0010:[<ffffffff81205b00>] 
c [<ffffffff81205b00>] mark_lock+0xb0/0x1290 kernel/locking/lockdep.c:3039
RSP: 0018:ffff8801d5c0ebf8  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801ca443948 RCX: 1ffff1003948872d
RDX: 1ffffffff078e7b6 RSI: ffff8801ca443948 RDI: ffffffff83c73db0
RBP: ffff8801d5c0ec40 R08: ffff8801ca443968 R09: 0000000000000001
R10: ffff8801ca442f80 R11: 1ffff10039488728 R12: ffffffff83c73d80
R13: 0000000000000040 R14: 0000000000000006 R15: ffff8801ca442f80
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc53cf41f00 CR3: 00000001ac32f000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801ca443920
c 0000000000000075
c 0000000000000006
c 0000000000000000
c
 ffff8801ca443948
c 0000000000000075
c 0000000000000007
c 0000000000000000
c
 ffff8801ca44396a
c ffff8801d5c0ee00
c ffffffff81207f8d
c ffff8801ca44381c
c
Call Trace:
 [<ffffffff81207f8d>] mark_irqflags kernel/locking/lockdep.c:2941 [inline]
 [<ffffffff81207f8d>] __lock_acquire+0xbdd/0x4a10 kernel/locking/lockdep.c:3302
 [<ffffffff8120c8d0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff82816c26>] __raw_spin_lock include/linux/spinlock_api_smp.h:144 [inline]
 [<ffffffff82816c26>] _raw_spin_lock+0x36/0x50 kernel/locking/spinlock.c:151
 [<ffffffff8141a061>] spin_lock include/linux/spinlock.h:302 [inline]
 [<ffffffff8141a061>] task_lock include/linux/sched.h:3257 [inline]
 [<ffffffff8141a061>] find_lock_task_mm+0xf1/0x270 mm/oom_kill.c:115
 [<ffffffff821effdf>] lowmem_scan+0x34f/0xaf0 drivers/staging/android/lowmemorykiller.c:134
 [<ffffffff81449cc6>] do_shrink_slab mm/vmscan.c:398 [inline]
 [<ffffffff81449cc6>] shrink_slab.part.8+0x3c6/0xa00 mm/vmscan.c:501
 [<ffffffff814557fd>] shrink_slab mm/vmscan.c:465 [inline]
 [<ffffffff814557fd>] shrink_node+0x1ed/0x740 mm/vmscan.c:2602
 [<ffffffff814560c7>] shrink_zones mm/vmscan.c:2749 [inline]
 [<ffffffff814560c7>] do_try_to_free_pages mm/vmscan.c:2791 [inline]
 [<ffffffff814560c7>] try_to_free_pages+0x377/0xb80 mm/vmscan.c:3002
 [<ffffffff81428a01>] __perform_reclaim mm/page_alloc.c:3324 [inline]
 [<ffffffff81428a01>] __alloc_pages_direct_reclaim mm/page_alloc.c:3345 [inline]
 [<ffffffff81428a01>] __alloc_pages_slowpath mm/page_alloc.c:3697 [inline]
 [<ffffffff81428a01>] __alloc_pages_nodemask+0x981/0x1bd0 mm/page_alloc.c:3862
 [<ffffffff814eb7e7>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff814eb7e7>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff814eb7e7>] alloc_slab_page mm/slub.c:1408 [inline]
 [<ffffffff814eb7e7>] allocate_slab mm/slub.c:1557 [inline]
 [<ffffffff814eb7e7>] new_slab+0x367/0x3d0 mm/slub.c:1635
 [<ffffffff814ed97d>] new_slab_objects mm/slub.c:2419 [inline]
 [<ffffffff814ed97d>] ___slab_alloc.constprop.33+0x2ed/0x470 mm/slub.c:2576
 [<ffffffff814edb50>] __slab_alloc.isra.25.constprop.32+0x50/0xa0 mm/slub.c:2618
 [<ffffffff814ee08c>] slab_alloc_node mm/slub.c:2681 [inline]
 [<ffffffff814ee08c>] slab_alloc mm/slub.c:2723 [inline]
 [<ffffffff814ee08c>] kmem_cache_alloc_trace+0x23c/0x2e0 mm/slub.c:2740
 [<ffffffff81b4bddf>] kmalloc include/linux/slab.h:490 [inline]
 [<ffffffff81b4bddf>] kzalloc include/linux/slab.h:636 [inline]
 [<ffffffff81b4bddf>] kobject_uevent_env+0x1ef/0xb80 lib/kobject_uevent.c:227
 [<ffffffff81b4c78f>] kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:374
 [<ffffffff81d9c7c8>] device_del+0x4b8/0x8e0 drivers/base/core.c:1302
 [<ffffffff823753c6>] netdev_unregister_kobject+0xe6/0x110 net/core/net-sysfs.c:1534
 [<ffffffff82303491>] rollback_registered_many+0x691/0xb50 net/core/dev.c:6883
 [<ffffffff8230d6f8>] unregister_netdevice_many+0x48/0x220 net/core/dev.c:7907
 [<ffffffff827ae96d>] ip6_tnl_destroy_tunnels net/ipv6/ip6_tunnel.c:2192 [inline]
 [<ffffffff827ae96d>] ip6_tnl_exit_net+0x3dd/0x5b0 net/ipv6/ip6_tunnel.c:2239
 [<ffffffff822e3d70>] ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:136
 [<ffffffff822e6ad2>] cleanup_net+0x3f2/0x8b0 net/core/net_namespace.c:473
 [<ffffffff81131001>] process_one_work+0x831/0x15f0 kernel/workqueue.c:2092
 [<ffffffff81131e96>] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Code: 
cb0 
c01 
c00 
c00 
c49 
c81 
cc4 
cc0 
c79 
cc6 
c83 
c49 
c8d 
c7c 
c24 
c30 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cfa 
c48 
cc1 
cea 
c03 
c80 
c3c 
c02 
c00 
c0f 
c85 
cbb 
c0d 
c00 
c00 
c<4d> 
c85 
c6c 
c24 
c30 
c74 
c5f 
c41 
cbd 
c01 
c00 
c00 
c00 
c48 
c83 
cc4 
c20 
c44 
c89 
ce8 
c5b 
c