INFO: task loop0:6091 blocked for more than 120 seconds.
      Not tainted 4.9.95-g142d4b5 #7
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
loop0           D27080  6091      2 0x00000000
 ffff8801d42eb000 ffff8801d33b24c0 ffff8801d33b24c0 ffff8801d4126000
 ffff8801db221b98 ffff88019f006df0 ffffffff839e240d 0000000041b58ab3
 ffffffff841c06a8 ffffffff81234350 0000000000000000 ffff8801db222468
Call Trace:
 [<ffffffff839e3a0f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839efe21>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e1bea>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff81e4f06c>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff81e4f06c>] bt_get.isra.8+0x27c/0x780 block/blk-mq-tag.c:141
 [<ffffffff81e4ff7c>] __blk_mq_get_tag block/blk-mq-tag.c:163 [inline]
 [<ffffffff81e4ff7c>] blk_mq_get_tag+0xac/0x220 block/blk-mq-tag.c:192
 [<ffffffff81e3f6aa>] __blk_mq_alloc_request+0x2a/0xaa0 block/blk-mq.c:196
 [<ffffffff81e41aab>] blk_mq_map_request.isra.38+0x3ab/0x900 block/blk-mq.c:1207
 [<ffffffff81e49ef6>] blk_sq_make_request+0x1d6/0x1220 block/blk-mq.c:1374
 [<ffffffff81e1ce2e>] generic_make_request+0x20e/0x9b0 block/blk-core.c:2055
 [<ffffffff81e1d680>] submit_bio+0xb0/0x460 block/blk-core.c:2126
 [<ffffffff8164106a>] dio_bio_submit fs/direct-io.c:420 [inline]
 [<ffffffff8164106a>] do_blockdev_direct_IO+0x35da/0x5a80 fs/direct-io.c:1301
 [<ffffffff816435b5>] __blockdev_direct_IO+0xa5/0xd0 fs/direct-io.c:1360
 [<ffffffff8162d160>] blkdev_direct_IO+0xa0/0xd0 fs/block_dev.c:183
 [<ffffffff8143c720>] generic_file_read_iter+0x660/0x1a90 mm/filemap.c:1952
 [<ffffffff8162fd65>] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1738
 [<ffffffff825ca833>] lo_rw_aio+0x6b3/0x8a0 drivers/block/loop.c:506
 [<ffffffff825cadf7>] do_req_filebacked drivers/block/loop.c:543 [inline]
 [<ffffffff825cadf7>] loop_handle_cmd drivers/block/loop.c:1698 [inline]
 [<ffffffff825cadf7>] loop_queue_work+0x3d7/0x2320 drivers/block/loop.c:1710
 [<ffffffff8119b109>] kthread_worker_fn+0x249/0x6b0 kernel/kthread.c:627
 [<ffffffff8119ad2d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f34dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
2 locks held by khungtaskd/518:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423cb0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3664:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d575c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3760:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f14b2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211cb02>] n_tty_read+0x202/0x16b0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor7/6231:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c719b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor7/6285:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c719b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor0/6234:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c719b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by syz-executor0/6284:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c719b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344

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

NMI backtrace for cpu 1
CPU: 1 PID: 518 Comm: khungtaskd Not tainted 4.9.95-g142d4b5 #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d85efd08 ffffffff81eb0f89 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b7d60 ffff8801d85efd40
 ffffffff81ebc2b7 0000000000000001 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81eb0f89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0f89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebc2b7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebc24a>] 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
 [<ffffffff81364c54>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c54>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c54>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c54>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad2d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f34dc>] 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 skipped: idling at pc 0xffffffff839f1f16