INFO: task syz-executor4:7990 blocked for more than 120 seconds.
      Not tainted 4.4.116-g17c7c49 #17
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D ffff8801cfd67a80 29688  7990   3852 0x00000004
 ffff8801cfd67a80 0000000000000001 0000000000000296 0000000041b58ab3
 ffffffff83fa9df4 ffffffff81220800 ffff8801db21fdb8 ffff8801db21fde0
 ffff8801db21f4d8 ffff8801cb4f8000 ffff8801d4898000 0000000000000000
Call Trace:
 [<ffffffff837668ca>] schedule+0x7a/0x1b0 kernel/sched/core.c:3353
 [<ffffffff81c96300>] blk_mq_freeze_queue_wait+0x120/0x240 block/blk-mq.c:95
 [<ffffffff81c9e87d>] blk_freeze_queue block/blk-mq.c:112 [inline]
 [<ffffffff81c9e87d>] blk_mq_freeze_queue+0x1d/0x20 block/blk-mq.c:121
 [<ffffffff8242033f>] loop_switch drivers/block/loop.c:610 [inline]
 [<ffffffff8242033f>] loop_change_fd drivers/block/loop.c:693 [inline]
 [<ffffffff8242033f>] lo_ioctl+0xfef/0x19c0 drivers/block/loop.c:1354
 [<ffffffff81cac47b>] __blkdev_driver_ioctl block/ioctl.c:288 [inline]
 [<ffffffff81cac47b>] blkdev_ioctl+0x4ab/0x1990 block/ioctl.c:584
 [<ffffffff815d1d4e>] block_ioctl+0xde/0x120 fs/block_dev.c:1625
 [<ffffffff81559e2a>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff81559e2a>] do_vfs_ioctl+0x7aa/0xee0 fs/ioctl.c:607
 [<ffffffff8155a5ef>] SYSC_ioctl fs/ioctl.c:622 [inline]
 [<ffffffff8155a5ef>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613
 [<ffffffff83774a1f>] entry_SYSCALL_64_fastpath+0x1c/0x98
INFO: lockdep is turned off.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 485 Comm: khungtaskd Not tainted 4.4.116-g17c7c49 #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb2f8000 task.stack: ffff8800bb390000
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bb397cb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: ffffffff8126a2f2
RDX: 0000000000000c00 RSI: 0000000000000002 RDI: ffffffffff5fb300
RBP: ffff8800bb397ce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: fffffbfff0ad7e24 R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426f3e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff47950c000 CR3: 00000000b1b1e000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426f3e0 ffffffff847ef800 fffffbfff08fd9b4 dffffc0000000000
 ffff8801db31bca0 ffff8800bb397d00 ffffffff810b99eb ffffffff839f61c0
 0000000000000003 ffff8800bb397d60 ffffffff81d0eed4 0000000000000001
Call Trace:
 [<ffffffff810b99eb>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d0eed4>] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85
 [<ffffffff810b9a84>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff81368caa>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff81368caa>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368caa>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368caa>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff811907e8>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff83774e45>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:506
Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 7b 2f 17 00 4c 89 e7 57 9d 0f 1f 
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.116-g17c7c49 #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b49800 task.stack: ffff8801d9b58000
RIP: 0010:[<ffffffff810c346c>]  [<ffffffff810c346c>] native_apic_mem_write+0xc/0x10 arch/x86/include/asm/apic.h:94
RSP: 0018:ffff8801d9b5fc08  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffffffff8426f3e0 RCX: 0000000000000020
RDX: 1ffffffff084de99 RSI: 000000000543a6c2 RDI: 0000000000000380
RBP: ffff8801d9b5fc08 R08: ffff88021fffd058 R09: 0000000000000004
R10: ffffed0043fffa09 R11: 0000000000000000 R12: 000000000543a6c2
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc34e3cb9b8 CR3: 00000000ad962000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d9b5fc28 ffffffff810b084a 0000000000000000 ffff8801db317fc0
 ffff8801d9b5fc68 ffffffff812cfdfa 0000003874147727 ffff8801db317fc0
 0000000000000001 ffff8801db319640 0000000000000001 0000000000000000
Call Trace:
 [<ffffffff810b084a>] apic_write arch/x86/include/asm/apic.h:392 [inline]
 [<ffffffff810b084a>] lapic_next_event+0x5a/0x90 arch/x86/kernel/apic/apic.c:458
 [<ffffffff812cfdfa>] clockevents_program_event+0x28a/0x350 kernel/time/clockevents.c:339
 [<ffffffff812d4c88>] tick_program_event+0xa8/0x110 kernel/time/tick-oneshot.c:47
 [<ffffffff812ac746>] hrtimer_force_reprogram kernel/time/hrtimer.c:601 [inline]
 [<ffffffff812ac746>] __remove_hrtimer+0x1f6/0x250 kernel/time/hrtimer.c:929
 [<ffffffff812ad173>] remove_hrtimer kernel/time/hrtimer.c:958 [inline]
 [<ffffffff812ad173>] hrtimer_try_to_cancel+0x2b3/0x660 kernel/time/hrtimer.c:1059
 [<ffffffff812ad542>] hrtimer_cancel+0x22/0x40 kernel/time/hrtimer.c:1079
 [<ffffffff812d583e>] tick_nohz_restart+0x1e/0x190 kernel/time/tick-sched.c:559
 [<ffffffff812d7897>] tick_nohz_restart_sched_tick kernel/time/tick-sched.c:726 [inline]
 [<ffffffff812d7897>] tick_nohz_idle_exit+0x247/0x3d0 kernel/time/tick-sched.c:946
 [<ffffffff81221875>] cpu_idle_loop kernel/sched/idle.c:267 [inline]
 [<ffffffff81221875>] cpu_startup_entry+0x2a5/0x8f0 kernel/sched/idle.c:301
 [<ffffffff810adcb4>] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242
Code: a0 06 00 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 be 01 00 00 00 48 89 e5 e8 f2 d1 1b 00 5d c3 55 89 ff 48 89 e5 89 b7 00 b0 5f ff <5d> c3 66 90 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 89 fb