INFO: task syz-executor.2:2134 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #17
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D ffff8801c1d07aa8 25472  2134      1 0x20020004
 ffff8801c1d07aa8 ffff8800b7baaf80 db2897230cfb948a ffff8800b7baaf80
 0000000000000002 ffff8800b7bab800 ffff8801db61f180 ffff8801db61f1a8
 ffff8801db61e898 ffff8800b4558000 ffff8800b7baaf80 ffffed00383a0001
Call Trace:
 [<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
 [<ffffffff8270a333>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388
 [<ffffffff8270c492>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8270c492>] mutex_lock_nested+0x3c2/0xb80 kernel/locking/mutex.c:621
 [<ffffffff81d48124>] __lo_release drivers/block/loop.c:1653 [inline]
 [<ffffffff81d48124>] lo_release+0x84/0x1b0 drivers/block/loop.c:1676
 [<ffffffff8154e4e1>] __blkdev_put+0x461/0x840 fs/block_dev.c:1535
 [<ffffffff8154f738>] blkdev_put+0x88/0x560 fs/block_dev.c:1600
 [<ffffffff8154fc9b>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1607
 [<ffffffff8149c8c6>] __fput+0x246/0x710 fs/file_table.c:208
 [<ffffffff8149ce16>] ____fput+0x16/0x20 fs/file_table.c:244
 [<ffffffff8112f352>] task_work_run+0x202/0x2b0 kernel/task_work.c:115
 [<ffffffff81003dca>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff81003dca>] exit_to_usermode_loop+0x14a/0x170 arch/x86/entry/common.c:188
 [<ffffffff810064b9>] prepare_exit_to_usermode arch/x86/entry/common.c:221 [inline]
 [<ffffffff810064b9>] syscall_return_slowpath arch/x86/entry/common.c:286 [inline]
 [<ffffffff810064b9>] do_syscall_32_irqs_on arch/x86/entry/common.c:336 [inline]
 [<ffffffff810064b9>] do_fast_syscall_32+0x7a9/0xa90 arch/x86/entry/common.c:397
 [<ffffffff8271a350>] sysenter_flags_fixed+0xd/0x1a
3 locks held by syz-executor.2/2134:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8154e13b>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1516
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81d480be>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1675
 #2:  (loop_ctl_mutex#2){+.+.+.}, at: [<ffffffff81d48124>] __lo_release drivers/block/loop.c:1653 [inline]
 #2:  (loop_ctl_mutex#2){+.+.+.}, at: [<ffffffff81d48124>] lo_release+0x84/0x1b0 drivers/block/loop.c:1676
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.174+ #17
task: ffffffff82e151c0 task.stack: ffffffff82e00000
RIP: 0010:[<ffffffff81272e53>]  [<ffffffff81272e53>] arch_local_save_flags arch/x86/include/asm/paravirt.h:807 [inline]
RIP: 0010:[<ffffffff81272e53>]  [<ffffffff81272e53>] arch_local_irq_save arch/x86/include/asm/paravirt.h:829 [inline]
RIP: 0010:[<ffffffff81272e53>]  [<ffffffff81272e53>] seqcount_lockdep_reader_access include/linux/seqlock.h:79 [inline]
RIP: 0010:[<ffffffff81272e53>]  [<ffffffff81272e53>] read_seqcount_begin include/linux/seqlock.h:163 [inline]
RIP: 0010:[<ffffffff81272e53>]  [<ffffffff81272e53>] ktime_get kernel/time/timekeeping.c:754 [inline]
RIP: 0010:[<ffffffff81272e53>]  [<ffffffff81272e53>] ktime_get+0x33/0x1c0 kernel/time/timekeeping.c:744
RSP: 0018:ffffffff82e07ae8  EFLAGS: 00000093
RAX: ffffffff82e151c0 RBX: 00000104e98f9c80 RCX: 1ffffffff0634988
RDX: 0000000000000000 RSI: ffffffff81272e53 RDI: ffff8801db617dfc
RBP: ffffffff82e07b38 R08: ffffffff84123508 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801db617dc0
R13: 1ffffffff05c0f6a R14: 0000000000000003 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000020db000 CR3: 00000000b4905000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000002 0000000000000046 0000000000000096 ffffffff84123508
 ffff8801db6198c0 00000104e98f9c80 ffff8801db617dc0 1ffffffff05c0f6a
 0000000000000003 ffffffff82e07bb0 ffffffff82e07bd8 ffffffff81284054
Call Trace:
 [<ffffffff81284054>] clockevents_program_event+0x1c4/0x3f0 kernel/time/clockevents.c:331
 [<ffffffff81289559>] tick_program_event+0xf9/0x180 kernel/time/tick-oneshot.c:47
 [<ffffffff812616ef>] hrtimer_reprogram kernel/time/hrtimer.c:664 [inline]
 [<ffffffff812616ef>] hrtimer_start_range_ns+0x101f/0x1450 kernel/time/hrtimer.c:1025
 [<ffffffff8128a742>] hrtimer_start_expires include/linux/hrtimer.h:407 [inline]
 [<ffffffff8128a742>] tick_nohz_restart+0x182/0x200 kernel/time/tick-sched.c:566
 [<ffffffff8128c317>] tick_nohz_restart_sched_tick kernel/time/tick-sched.c:726 [inline]
 [<ffffffff8128c317>] tick_nohz_idle_exit+0x247/0x3d0 kernel/time/tick-sched.c:946
 [<ffffffff811ebd0a>] cpu_idle_loop kernel/sched/idle.c:267 [inline]
 [<ffffffff811ebd0a>] cpu_startup_entry+0x73a/0x810 kernel/sched/idle.c:301
 [<ffffffff827055f9>] rest_init+0x190/0x199 init/main.c:410
 [<ffffffff831d58a0>] start_kernel+0x64a/0x67e init/main.c:682
 [<ffffffff831d430a>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff831d4443>] x86_64_start_kernel+0x137/0x15a arch/x86/kernel/head64.c:185
Code: 41 55 41 54 53 48 83 ec 28 e8 ba 67 09 00 8b 05 18 23 f3 01 85 c0 0f 85 6c 01 00 00 49 bf 00 00 00 00 00 fc ff df e8 9d 67 09 00 <9c> 58 0f 1f 44 00 00 48 89 c3 fa 66 0f 1f 44 00 00 e8 b7 5b f8 
NMI backtrace for cpu 1
CPU: 1 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #17
task: ffff8801da6f4740 task.stack: ffff8800001d0000
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800001d7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001d7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001e51bb0 CR3: 00000001d57e8000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001d7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001d7d30 ffffffff81ab8252
Call Trace:
 [<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae lib/nmi_backtrace.c:85
 [<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813b4762>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1