INFO: task loop0:9817 blocked for more than 120 seconds.
      Not tainted 4.9.97-g19bd3e3 #15
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
loop0           D27080  9817      2 0x00000000
 ffff8801d72ce000 ffff8801b7464540 ffff8801c796d500 ffff8801a1cf3000
 ffff8801db321b98 ffff8801b5af6df0 ffffffff839e375d 0000000041b58ab3
 ffffffff843c0c78 ffffffff81234380 0000000000000000 ffff8801db322468
Call Trace:
 [<ffffffff839e4d5f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f1171>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e2f3a>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff81e4ec4c>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff81e4ec4c>] bt_get.isra.8+0x27c/0x780 block/blk-mq-tag.c:141
 [<ffffffff81e4fb5c>] __blk_mq_get_tag block/blk-mq-tag.c:163 [inline]
 [<ffffffff81e4fb5c>] blk_mq_get_tag+0xac/0x220 block/blk-mq-tag.c:192
 [<ffffffff81e3f28a>] __blk_mq_alloc_request+0x2a/0xaa0 block/blk-mq.c:196
 [<ffffffff81e4168b>] blk_mq_map_request.isra.38+0x3ab/0x900 block/blk-mq.c:1207
 [<ffffffff81e49ad6>] blk_sq_make_request+0x1d6/0x1220 block/blk-mq.c:1374
 [<ffffffff81e1ca0e>] generic_make_request+0x20e/0x9b0 block/blk-core.c:2055
 [<ffffffff81e1d260>] submit_bio+0xb0/0x460 block/blk-core.c:2126
 [<ffffffff816410aa>] dio_bio_submit fs/direct-io.c:420 [inline]
 [<ffffffff816410aa>] do_blockdev_direct_IO+0x35da/0x5a80 fs/direct-io.c:1301
 [<ffffffff816435f5>] __blockdev_direct_IO+0xa5/0xd0 fs/direct-io.c:1360
 [<ffffffff8162d1a0>] blkdev_direct_IO+0xa0/0xd0 fs/block_dev.c:183
 [<ffffffff8143c760>] generic_file_read_iter+0x660/0x1a90 mm/filemap.c:1951
 [<ffffffff8162fda5>] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1738
 [<ffffffff825ca893>] lo_rw_aio+0x6b3/0x8a0 drivers/block/loop.c:506
 [<ffffffff825cae57>] do_req_filebacked drivers/block/loop.c:543 [inline]
 [<ffffffff825cae57>] loop_handle_cmd drivers/block/loop.c:1698 [inline]
 [<ffffffff825cae57>] loop_queue_work+0x3d7/0x2320 drivers/block/loop.c:1710
 [<ffffffff8119b139>] kthread_worker_fn+0x249/0x6b0 kernel/kthread.c:627
 [<ffffffff8119ad5d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f481c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646ec>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646ec>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423ce0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3675:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d579c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3771:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f2802>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211c8a2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/3863:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c71fb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor5/10282:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c71fb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor5/10325:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c71fb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor5/10326:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c71fb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor5/10328:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c71fb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by blkid/10343:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c71fb>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.97-g19bd3e3 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d91a7d08 ffffffff81eb0b69 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b7d60 ffff8801d91a7d40
 ffffffff81ebbe97 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb0b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebbe97>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebbe2a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7e64>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364c84>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c84>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c84>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c84>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad5d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f481c>] 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 4.9.97-g19bd3e3 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84629800 task.stack: ffffffff84600000
RIP: 0010:[<ffffffff8123257a>] 
c [<ffffffff8123257a>] mark_lock+0xaa/0x1280 kernel/locking/lockdep.c:3039
RSP: 0018:ffffffff84607b48  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffffffff8462a0c8 RCX: 1ffffffff08c541d
RDX: 1ffffffff0ab1970 RSI: ffffffff8462a0c8 RDI: ffffffff8558cb80
RBP: ffffffff84607b90 R08: ffffffff8462a0e8 R09: 0000000000000000
R10: ffffffff84629800 R11: 0000000000000001 R12: ffffffff8558cb50
R13: 0000000000001000 R14: 000000000000000c R15: ffffffff84629800
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000a33000 CR3: 00000001bafd8000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000001
c dffffc0000000000
c ffffffff84607bf0
c ffffffff812c9b9c
c
 ffffffff8462a0c8
c 0000000000000024
c 0000000000000000
c ffffffff8462a0b4
c
 0000000000000000
c ffffffff84607d50
c ffffffff812349d4
c 0000000000000046
c
Call Trace:
 [<ffffffff812349d4>] __lock_acquire+0x654/0x4070 kernel/locking/lockdep.c:3306
 [<ffffffff81238e60>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff811a0b48>] rcu_lock_acquire include/linux/rcupdate.h:493 [inline]
 [<ffffffff811a0b48>] rcu_read_lock include/linux/rcupdate.h:875 [inline]
 [<ffffffff811a0b48>] __atomic_notifier_call_chain kernel/notifier.c:182 [inline]
 [<ffffffff811a0b48>] atomic_notifier_call_chain+0x48/0x140 kernel/notifier.c:193
 [<ffffffff81136c3e>] idle_notifier_call_chain+0x1e/0x30 kernel/cpu.c:1975
 [<ffffffff81069f4b>] __exit_idle arch/x86/kernel/process.c:252 [inline]
 [<ffffffff81069f4b>] arch_cpu_idle_exit+0x1b/0x20 arch/x86/kernel/process.c:273
 [<ffffffff81220d29>] cpu_idle_loop kernel/sched/idle.c:250 [inline]
 [<ffffffff81220d29>] cpu_startup_entry+0x179/0x380 kernel/sched/idle.c:303
 [<ffffffff839e052c>] rest_init+0x183/0x189 init/main.c:409
 [<ffffffff84c96943>] start_kernel+0x67e/0x6b2 init/main.c:664
 [<ffffffff84c9529a>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff84c953db>] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:177
Code: 
c01 
c00 
c00 
c49 
c81 
cec 
cb0 
c01 
c00 
c00 
c49 
c81 
cc4 
c40 
c90 
c58 
c85 
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 
c<0f> 
c85 
c41 
c0e 
c00 
c00 
c4d 
c85 
c6c 
c24 
c30 
c74 
c5f 
c41 
cbd 
c01 
c00 
c00 
c00 
c48 
c83 
c