IPVS: Creating netns size=2536 id=10
syz-executor1 (6150) used greatest stack depth: 23480 bytes left
INFO: task syz-executor5:6142 blocked for more than 120 seconds.
      Not tainted 4.9.103-g70c65e4 #37
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D28760  6142   3880 0x00000004
 ffff8801d302b000 ffff8801d3cfdf80 ffff8801d3f49500 ffff88019c5ae000
 ffff8801db321c18 ffff88019bd1f9f0 ffffffff839e711d 0000000000000002
 0000000041b58ab3 ffffffff843b9803 00ffffff81221330 ffff8801db3224e8
Call Trace:
 [<ffffffff839e871f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff81e40b64>] blk_mq_freeze_queue_wait+0x114/0x230 block/blk-mq.c:75
 [<ffffffff81e49e5d>] blk_freeze_queue block/blk-mq.c:92 [inline]
 [<ffffffff81e49e5d>] blk_mq_freeze_queue+0x1d/0x20 block/blk-mq.c:101
 [<ffffffff825ca372>] loop_switch drivers/block/loop.c:599 [inline]
 [<ffffffff825ca372>] loop_change_fd drivers/block/loop.c:685 [inline]
 [<ffffffff825ca372>] lo_ioctl+0x722/0x1aa0 drivers/block/loop.c:1350
 [<ffffffff81e57066>] __blkdev_driver_ioctl block/ioctl.c:294 [inline]
 [<ffffffff81e57066>] blkdev_ioctl+0x7b6/0x1a70 block/ioctl.c:590
 [<ffffffff8163259e>] block_ioctl+0xde/0x120 fs/block_dev.c:1688
 [<ffffffff815b27cc>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b27cc>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b27cc>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b384f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b384f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f8013>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136688c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136688c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425e10>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3674:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d7a4c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3770:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f61c2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211f192>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor5/6142:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c9cdb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.103-g70c65e4 #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8a47d08 ffffffff81eb3469 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9590 ffff8801d8a47d40
 ffffffff81ebe767 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb3469>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3469>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebe767>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebe6fa>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9694>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366e24>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366e24>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366e24>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366e24>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119cead>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f81dc>] 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: 0 Comm: swapper/0 Not tainted 4.9.103-g70c65e4 #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84629800 task.stack: ffffffff84600000
RIP: 0010:[<ffffffff811d0503>] 
c [<ffffffff811d0503>] constant_test_bit arch/x86/include/asm/bitops.h:311 [inline]
RIP: 0010:[<ffffffff811d0503>] 
c [<ffffffff811d0503>] got_nohz_idle_kick kernel/sched/core.c:625 [inline]
RIP: 0010:[<ffffffff811d0503>] 
c [<ffffffff811d0503>] scheduler_ipi+0x2f3/0x4e0 kernel/sched/core.c:1829
RSP: 0018:ffff8801db207fa8  EFLAGS: 00000046
RAX: 0000000000000003 RBX: 0000000000021c00 RCX: 1ffffffff0886280
RDX: 1ffff1003b64438f RSI: ffffffff81f1aecb RDI: ffff8801db221c78
RBP: ffff8801db207fd0 R08: 0000000000000001 R09: 0000000000000006
R10: ffffed0043fffa01 R11: 0000000000000001 R12: ffff8801db221c00
R13: ffff8801db200000 R14: ffffffff84c5e288 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdc1492148 CR3: 00000001baad1000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff84629800
c ffffffff84431860
c 0000000000000000
c 0000000000000000
c
 ffffffff84c5e288
c ffff8801db207fe8
c ffffffff839fc79c
c ffffffff84c4e148
c
 ffffffff84607dc0
c ffffffff839fa310
c ffffffff84607d18
c <EOI> 
c 0000000000000000
c
Call Trace:
 <IRQ> 
d [<ffffffff839fc79c>] __smp_reschedule_interrupt arch/x86/kernel/smp.c:262 [inline]
 <IRQ> 
d [<ffffffff839fc79c>] smp_reschedule_interrupt+0x6c/0x90 arch/x86/kernel/smp.c:269
 [<ffffffff839fa310>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:671
 <EOI> 
d [<ffffffff839f6c26>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff839f6265>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline]
 [<ffffffff839f6265>] default_idle+0x55/0x360 arch/x86/kernel/process.c:437
 [<ffffffff8106ab20>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:428
 [<ffffffff839f7085>] default_idle_call+0x45/0x60 kernel/sched/idle.c:97
 [<ffffffff81222fb5>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81222fb5>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81222fb5>] cpu_startup_entry+0x2b5/0x380 kernel/sched/idle.c:303
 [<ffffffff839e3eec>] rest_init+0x183/0x189 init/main.c:409
 [<ffffffff84c97943>] start_kernel+0x67e/0x6b2 init/main.c:664
 [<ffffffff84c9629a>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff84c963db>] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:177
Code: 
c14 
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cfc 
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c01 
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c49 
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c24 
c78 
c<a8> 
c02 
c0f 
c84 
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cfe 
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cff 
c48 
cb8 
c00 
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cfc 
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c49 
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cdc 
c