Free memory is -13412kB above reserved
lowmemorykiller: Killing 'syz-executor0' (11718) (tgid 11716), adj 1000,
   to free 32932kB on behalf of 'syz-fuzzer' (2062) because
   cache 204kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13412kB above reserved
INFO: task kworker/0:1:23 blocked for more than 140 seconds.
      Not tainted 4.9.135+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:1     D26904    23      2 0x80000000
Workqueue: events linkwatch_event
 ffff8801da732f80 0000000000000000 ffff8801d51b8000 ffff8801ae73af80
 ffff8801db621018 ffff8801d9c3fae8 ffffffff82806912 0000000000000002
 ffff8801da733830 ffff8801ae73b778 00ff8801da732f80 ffff8801db6218f0
Call Trace:
 [<ffffffff82807e3f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828087c3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff8280a83d>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8280a83d>] mutex_lock_nested+0x38d/0x900 kernel/locking/mutex.c:621
 [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff82357ede>] linkwatch_event+0xe/0x60 net/core/link_watch.c:236
 [<ffffffff81130d61>] process_one_work+0x831/0x1530 kernel/workqueue.c:2092
 [<ffffffff81131b36>] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226
 [<ffffffff811428dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82816d5c>] 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: [<ffffffff81130c6c>] process_one_work+0x73c/0x1530 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff81130ca4>] process_one_work+0x774/0x1530 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
3 locks held by kworker/0:1/23:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130c6c>] process_one_work+0x73c/0x1530 kernel/workqueue.c:2085
 #1:  ((linkwatch_work).work){+.+...}, at: [<ffffffff81130ca4>] process_one_work+0x774/0x1530 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131bb4c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131bb4c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe314>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2024:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82814c62>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d36fc2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor2/5911:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor1/6021:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor0/6260:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor0/6320:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82340e77>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.135+ #19
 ffff8801d9907d08 ffffffff81b42b89 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff81098330 ffff8801d9907d40
 ffffffff81b4dc99 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b42b89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42b89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4dc99>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4dc2c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff81098434>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131c0dd>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c0dd>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c0dd>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c0dd>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff811428dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82816d5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2061 Comm: syz-fuzzer Not tainted 4.9.135+ #19
task: ffff8801d0cac740 task.stack: ffff8801cdd38000
RIP: 0010:[<ffffffff81206a91>] 
c [<ffffffff81206a91>] mark_held_locks+0xa1/0x130 kernel/locking/lockdep.c:2652
RSP: 0000:ffff8801cdd3f4d8  EFLAGS: 00000002
RAX: 1ffff1003a195a02 RBX: 0000000000000000 RCX: 1ffff1003a195a0c
RDX: 0000000000000002 RSI: ffff8801d0cacff0 RDI: ffff8801d0cad012
RBP: ffff8801cdd3f518 R08: ffff8801d0cad060 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d0cacff0
R13: ffffed003a1959fd R14: ffff8801d0cac740 R15: dffffc0000000000
FS:  000000c420026068(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ce56 CR3: 00000001cf1bb000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000400000003
c ffff8801d0cacfe8
c 0000000600000007
c ffff8801d0cac740
c
 ffffffff8148e420
c 0000000000000000
c ffffffff83128b60
c dffffc0000000000
c
 ffff8801cdd3f538
c ffffffff81206eab
c ffff8801cdd3f650
c ffff8801cdd3f668
c
Call Trace:
 [<ffffffff81206eab>] __trace_hardirqs_on_caller kernel/locking/lockdep.c:2689 [inline]
 [<ffffffff81206eab>] trace_hardirqs_on_caller+0x38b/0x590 kernel/locking/lockdep.c:2736
 [<ffffffff812070bd>] trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2743
 [<ffffffff8148e420>] count_shadow_nodes+0x80/0x190 mm/workingset.c:349
 [<ffffffff81449a1f>] do_shrink_slab mm/vmscan.c:326 [inline]
 [<ffffffff81449a1f>] shrink_slab.part.8+0x1cf/0xa00 mm/vmscan.c:501
 [<ffffffff8145574d>] shrink_slab mm/vmscan.c:465 [inline]
 [<ffffffff8145574d>] shrink_node+0x1ed/0x740 mm/vmscan.c:2602
 [<ffffffff81456017>] shrink_zones mm/vmscan.c:2749 [inline]
 [<ffffffff81456017>] do_try_to_free_pages mm/vmscan.c:2791 [inline]
 [<ffffffff81456017>] try_to_free_pages+0x377/0xb80 mm/vmscan.c:3002
 [<ffffffff81428951>] __perform_reclaim mm/page_alloc.c:3324 [inline]
 [<ffffffff81428951>] __alloc_pages_direct_reclaim mm/page_alloc.c:3345 [inline]
 [<ffffffff81428951>] __alloc_pages_slowpath mm/page_alloc.c:3697 [inline]
 [<ffffffff81428951>] __alloc_pages_nodemask+0x981/0x1bd0 mm/page_alloc.c:3862
 [<ffffffff814156f1>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff814156f1>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff814156f1>] alloc_pages_node include/linux/gfp.h:460 [inline]
 [<ffffffff814156f1>] __page_cache_alloc include/linux/pagemap.h:208 [inline]
 [<ffffffff814156f1>] page_cache_read mm/filemap.c:2007 [inline]
 [<ffffffff814156f1>] filemap_fault+0xaf1/0x1110 mm/filemap.c:2192
 [<ffffffff816e76b1>] ext4_filemap_fault+0x71/0xa0 fs/ext4/inode.c:5853
 [<ffffffff81492e73>] __do_fault+0x223/0x500 mm/memory.c:2833
 [<ffffffff814a3616>] do_read_fault mm/memory.c:3180 [inline]
 [<ffffffff814a3616>] do_fault mm/memory.c:3315 [inline]
 [<ffffffff814a3616>] handle_pte_fault mm/memory.c:3516 [inline]
 [<ffffffff814a3616>] __handle_mm_fault mm/memory.c:3603 [inline]
 [<ffffffff814a3616>] handle_mm_fault+0x1326/0x2350 mm/memory.c:3640
 [<ffffffff810b2a93>] __do_page_fault+0x403/0xa60 arch/x86/mm/fault.c:1406
 [<ffffffff810b3147>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1469
 [<ffffffff82817bb5>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:951
Code: 
cd0 
c4d 
c8d 
ca6 
cb0 
c08 
c00 
c00 
c49 
cc1 
ced 
c03 
c4d 
c01 
cfd 
c48 
c63 
cc3 
c48 
c8d 
c04 
c80 
c49 
c8d 
c34 
cc4 
c48 
c8d 
c7e 
c22 
c48 
c89 
cf8 
c48 
c89 
cfa 
c48 
cc1 
ce8 
c03 
c83 
ce2 
c07 
c<42> 
c0f 
cb6 
c04 
c38 
c38 
cd0 
c7f 
c04 
c84 
cc0 
c75 
c5e 
c0f 
cb6 
c46 
c22 
c8b 
c55 
cd4 
ca8 
c