Free memory is 47956kB above reserved
lowmemorykiller: Killing 'syz-executor696' (20369) (tgid 20367), adj 1000,
   to free 10980kB on behalf of 'syz-executor696' (20369) because
   cache 1028kB is below limit 65536kB for oom_score_adj 12
   Free memory is 47956kB above reserved
INFO: task init:13835 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D28888 13835      1 0x00000000
 ffff880006cc0000 ffff8801d6a3d280 ffff8801c8c24200 ffff8800514f4740
 ffff8801db621018 ffff880006ccf580 ffffffff828075c2 ffff880006cc08b0
 000000000000015c 0000000000000000 0000000000000000 ffff8801db6218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828142d5>] schedule_timeout+0x735/0xe20 kernel/time/timer.c:1771
 [<ffffffff828108c1>] __down_common kernel/locking/semaphore.c:221 [inline]
 [<ffffffff828108c1>] __down+0x191/0x2b0 kernel/locking/semaphore.c:238
 [<ffffffff811fcbfe>] down+0x5e/0x80 kernel/locking/semaphore.c:61
 [<ffffffff812223ac>] console_lock+0x2c/0x80 kernel/printk/printk.c:2217
 [<ffffffff8122793c>] console_device+0x1c/0xc0 kernel/printk/printk.c:2554
 [<ffffffff81d2be15>] tty_lookup_driver drivers/tty/tty_io.c:2008 [inline]
 [<ffffffff81d2be15>] tty_open_by_driver drivers/tty/tty_io.c:2053 [inline]
 [<ffffffff81d2be15>] tty_open+0x6f5/0xdf0 drivers/tty/tty_io.c:2130
 [<ffffffff81517bdd>] chrdev_open+0x22d/0x5c0 fs/char_dev.c:392
 [<ffffffff81501e3f>] do_dentry_open+0x3ef/0xc90 fs/open.c:766
 [<ffffffff8150576c>] vfs_open+0x11c/0x210 fs/open.c:879
 [<ffffffff8153c542>] do_last fs/namei.c:3410 [inline]
 [<ffffffff8153c542>] path_openat+0x542/0x2790 fs/namei.c:3534
 [<ffffffff81541617>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8150617d>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8150645d>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff8150645d>] SyS_open+0x2d/0x40 fs/open.c:1085
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
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/1897:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2024:
 #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 init/13835:
 #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/13836:
 #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/13837:
 #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/13838:
 #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/13839:
 #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/13840:
 #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

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

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: 20369 Comm: syz-executor696 Not tainted 4.9.141+ #1
task: ffff88009e305f00 task.stack: ffff880077cb8000
RIP: 0010:[<ffffffff8131ba86>] 
c [<ffffffff8131ba86>] __sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:100
RSP: 0018:ffff880077cbee48  EFLAGS: 00000246
RAX: ffff88009e305f00 RBX: ffff8800451497c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff821f0180 RDI: ffffffff841eb840
RBP: ffff880077cbee48 R08: ffff88009e306870 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: dffffc0000000000
R13: 000000000000067b R14: ffff8800451497c0 R15: 0000000000004000
FS:  00007f52a269a700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000930212 CR3: 000000000f7f9000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff880077cbeef8
c ffffffff821f0180
c ffffffff821efede
c ffff880000004f91
c
 0000000000000404
c 0000000000000246
c ffff88009e305f00
c ffffffff830cc2e0
c
 ffff880077cbefd0
c fffffbfff0601200
c 000006ff77cbeec0
c ffff880045149f80
c
Call Trace:
 [<ffffffff821f0180>] lowmem_scan+0x4f0/0xaf0 drivers/staging/android/lowmemorykiller.c:154
 [<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
 [<ffffffff814a382f>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff814a382f>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff814a382f>] alloc_pages_node include/linux/gfp.h:460 [inline]
 [<ffffffff814a382f>] alloc_zeroed_user_highpage_movable include/linux/highmem.h:183 [inline]
 [<ffffffff814a382f>] do_anonymous_page mm/memory.c:2761 [inline]
 [<ffffffff814a382f>] handle_pte_fault mm/memory.c:3514 [inline]
 [<ffffffff814a382f>] __handle_mm_fault mm/memory.c:3603 [inline]
 [<ffffffff814a382f>] handle_mm_fault+0x14bf/0x2350 mm/memory.c:3640
 [<ffffffff810b2b33>] __do_page_fault+0x403/0xa60 arch/x86/mm/fault.c:1406
 [<ffffffff810b31e7>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1469
 [<ffffffff828188b5>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:951
 [<ffffffff822d91cc>] skb_copy_datagram_iter+0x38c/0x910 net/core/datagram.c:409
 [<ffffffff826785be>] skb_copy_datagram_msg include/linux/skbuff.h:3073 [inline]
 [<ffffffff826785be>] unix_stream_read_actor+0x7e/0xb0 net/unix/af_unix.c:2474
 [<ffffffff8267f3c7>] unix_stream_read_generic+0xae7/0x1f10 net/unix/af_unix.c:2395
 [<ffffffff82680a83>] unix_stream_recvmsg+0xb3/0xf0 net/unix/af_unix.c:2490
 [<ffffffff822a1066>] sock_recvmsg_nosec net/socket.c:750 [inline]
 [<ffffffff822a1066>] sock_recvmsg+0xc6/0x110 net/socket.c:757
 [<ffffffff822a4a5b>] SYSC_recvfrom net/socket.c:1735 [inline]
 [<ffffffff822a4a5b>] SyS_recvfrom+0x20b/0x380 net/socket.c:1707
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
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c<83> 
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c