lowmemorykiller: Killing 'syz-executor.1' (5881) (tgid 5881), adj 1000,
   to free 34836kB on behalf of 'syz-fuzzer' (2058) because
   cache 364kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13332kB above reserved
INFO: task syz-executor.2:2098 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #23
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D24312  2098      1 0x20020004
 ffff8801d2722f80 ffff8801d1635280 ffff8801ced46e00 ffff8801d27217c0
 ffff8801db621018 ffff8801acbdf930 ffffffff828075c2 ffffffff83c27940
 0000000041b58ab3 ffffffff82e33920 00ffffff83c7a7d0 ffff8801db6218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828142d5>] schedule_timeout+0x735/0xe20 kernel/time/timer.c:1771
 [<ffffffff8280a63f>] do_wait_for_common kernel/sched/completion.c:75 [inline]
 [<ffffffff8280a63f>] __wait_for_common kernel/sched/completion.c:93 [inline]
 [<ffffffff8280a63f>] wait_for_common+0x3ef/0x5d0 kernel/sched/completion.c:101
 [<ffffffff8280a838>] wait_for_completion+0x18/0x20 kernel/sched/completion.c:122
 [<ffffffff81243b37>] __wait_rcu_gp+0x137/0x1b0 kernel/rcu/update.c:369
 [<ffffffff8124c21a>] synchronize_rcu.part.55+0xfa/0x110 kernel/rcu/tree_plugin.h:684
 [<ffffffff8124c257>] synchronize_rcu+0x27/0x90 kernel/rcu/tree_plugin.h:685
 [<ffffffff8156fb0e>] namespace_unlock+0xfe/0x120 fs/namespace.c:1440
 [<ffffffff81577a60>] do_umount fs/namespace.c:1642 [inline]
 [<ffffffff81577a60>] SYSC_umount fs/namespace.c:1737 [inline]
 [<ffffffff81577a60>] SyS_umount+0x670/0xcf0 fs/namespace.c:1706
 [<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
 [<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
 [<ffffffff82818de0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by kworker/0:0/4:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by kworker/1:0/18:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
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/1898:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2025:
 #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
2 locks held by kworker/0:2/2193:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by kworker/0:3/3400:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
1 lock held by syz-executor.2/4831:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d276f9>] tty_release+0xb79/0xe90 drivers/tty/tty_io.c:1938
1 lock held by syz-executor.2/4905:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d276f9>] tty_release+0xb79/0xe90 drivers/tty/tty_io.c:1938
1 lock held by syz-executor.5/7109:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by kworker/1:4/7316:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by kworker/1:5/7318:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&rew.rew_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by kworker/1:6/7319:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
1 lock held by syz-executor.5/7329:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] __sock_release+0x8b/0x260 net/socket.c:604
1 lock held by +/7347:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] __sock_release+0x8b/0x260 net/socket.c:604
1 lock held by syz-executor.3/9466:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] __sock_release+0x8b/0x260 net/socket.c:604
2 locks held by syz-executor.3/9522:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] __sock_release+0x8b/0x260 net/socket.c:604
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<ffffffff8124a7b7>] exp_funnel_lock kernel/rcu/tree_exp.h:289 [inline]
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<ffffffff8124a7b7>] _synchronize_rcu_expedited+0x3a7/0x840 kernel/rcu/tree_exp.h:569
1 lock held by syz-executor.3/9806:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] __sock_release+0x8b/0x260 net/socket.c:604
1 lock held by syz-executor.3/9857:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] inode_lock include/linux/fs.h:766 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<ffffffff8229bd8b>] __sock_release+0x8b/0x260 net/socket.c:604
1 lock held by syz-executor.0/11337:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.0/11374:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.4/11392:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.4/11428:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
4 locks held by kworker/u4:10/11905:
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.+.}, at: [<ffffffff822e681f>] cleanup_net+0x13f/0x8b0 net/core/net_namespace.c:439
 #3:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.2/14388:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.2/14391:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.2/16484:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by syz-executor.2/16536:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<ffffffff8124a749>] exp_funnel_lock kernel/rcu/tree_exp.h:256 [inline]
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<ffffffff8124a749>] _synchronize_rcu_expedited+0x339/0x840 kernel/rcu/tree_exp.h:569
1 lock held by syz-executor.4/17775:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.4/17833:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by kworker/0:1/19489:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
1 lock held by init/19701:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/19702:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/19703:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/19704:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/19705:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/19706:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
2 locks held by kworker/1:1/19707:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by kworker/1:2/19708:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by kworker/1:3/19709:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
3 locks held by kworker/1:8/19713:
 #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

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #23
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000000 0000000000000000 0000000000000003
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 33 Comm: kswapd0 Not tainted 4.9.141+ #23
task: ffff8801d8410000 task.stack: ffff8801d8418000
RIP: 0010:[<ffffffff81205b00>] 
c [<ffffffff81205b00>] mark_lock+0xb0/0x1290 kernel/locking/lockdep.c:3039
RSP: 0018:ffff8801d841f5d8  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801d8410900 RCX: 1ffff1003b082124
RDX: 1ffffffff078e7b6 RSI: ffff8801d8410900 RDI: ffffffff83c73db0
RBP: ffff8801d841f620 R08: ffff8801d8410920 R09: 0000000000000000
R10: ffff8801d8410000 R11: 1ffff1003b08211f R12: ffffffff83c73d80
R13: 0000000000000004 R14: 0000000000000002 R15: ffff8801d8410000
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000798205 CR3: 00000001cf188000 CR4: 00000000001606b0
Stack:
 0000000000000002
c 0000000000000000
c ffff8801d8410922
c ffff8801d841f7b0
c
 ffff8801d8410900
c 0000000000000075
c 0000000000000002
c 0000000000000000
c
 ffff8801d8410922
c ffff8801d841f7e0
c ffffffff81208460
c 0000000000000000
c
Call Trace:
 [<ffffffff81208460>] mark_irqflags kernel/locking/lockdep.c:2937 [inline]
 [<ffffffff81208460>] __lock_acquire+0x10b0/0x4a10 kernel/locking/lockdep.c:3302
 [<ffffffff8120d17c>] __lock_release kernel/locking/lockdep.c:3571 [inline]
 [<ffffffff8120d17c>] lock_release+0x5fc/0xc20 kernel/locking/lockdep.c:3775
 [<ffffffff8141a0cb>] rcu_lock_release include/linux/rcupdate.h:498 [inline]
 [<ffffffff8141a0cb>] rcu_read_unlock include/linux/rcupdate.h:931 [inline]
 [<ffffffff8141a0cb>] find_lock_task_mm+0x15b/0x270 mm/oom_kill.c:122
 [<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
 [<ffffffff814570b9>] kswapd_shrink_node mm/vmscan.c:3202 [inline]
 [<ffffffff814570b9>] balance_pgdat mm/vmscan.c:3319 [inline]
 [<ffffffff814570b9>] kswapd+0x7e9/0x13b0 mm/vmscan.c:3512
 [<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