INFO: task syz-executor1:5493 blocked for more than 120 seconds.
      Not tainted 4.9.88-g71df7bb #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D29824  5493   3876 0x20020004
 ffff8801d8b51800 ffff8801b9f364c0 ffff8801cb18f480 ffff8801d8bb6000
 ffff8801db221b98 ffff8801bcec7c98 ffffffff838a69cb 0000000000000001
 0000000000000007 00ff8801d8b51800 ffff8801db222468 ffff8801db222490
Call Trace:
 [<ffffffff838a7f6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a88f3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3583
 [<ffffffff838ad692>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838ad692>] mutex_lock_nested+0x312/0x870 kernel/locking/mutex.c:621
 [<ffffffff824baab6>] loop_control_ioctl+0x176/0x300 drivers/block/loop.c:1913
 [<ffffffff8167db3f>] C_SYSC_ioctl fs/compat_ioctl.c:1602 [inline]
 [<ffffffff8167db3f>] compat_SyS_ioctl+0x15f/0x2050 fs/compat_ioctl.c:1549
 [<ffffffff81006f95>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006f95>] do_fast_syscall_32+0x2f5/0x870 arch/x86/entry/common.c:387
 [<ffffffff838b9190>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813735a5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813735a5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81238570>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3655:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d43cf>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3783:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b5c42>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200b3a4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
2 locks held by syz-executor1/5493:
 #0:  (loop_index_mutex){+.+.+.}, at: [<ffffffff824ba9ba>] loop_control_ioctl+0x7a/0x300 drivers/block/loop.c:1899
 #1:  (&lo->lo_ctl_mutex#2){+.+...}, at: [<ffffffff824baab6>] loop_control_ioctl+0x176/0x300 drivers/block/loop.c:1913
1 lock held by syz-executor1/5520:
 #0:  (loop_index_mutex){+.+.+.}, at: [<ffffffff824ba9ba>] loop_control_ioctl+0x7a/0x300 drivers/block/loop.c:1899
1 lock held by syz-executor1/5528:
 #0:  (loop_index_mutex){+.+.+.}, at: [<ffffffff824ba9ba>] loop_control_ioctl+0x7a/0x300 drivers/block/loop.c:1899
1 lock held by syz-executor5/5491:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268
1 lock held by syz-executor5/5502:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff824b84ff>] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337
1 lock held by syz-executor5/5516:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff824b84ff>] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337
1 lock held by syz-executor5/5527:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff824b84ff>] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337
2 locks held by syz-executor3/5483:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff824b84ff>] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337
 #1:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81d37d9e>] blkdev_reread_part+0x1e/0x40 block/ioctl.c:189
1 lock held by syz-executor3/5504:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268
1 lock held by syz-executor3/5509:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff824b84ff>] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337
2 locks held by blkid/5495:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff824b345b>] lo_open+0x1b/0xa0 drivers/block/loop.c:1548
1 lock held by syz-executor7/5535:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268
1 lock held by syz-executor7/5539:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268
1 lock held by syz-executor6/5542:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268
1 lock held by syz-executor6/5543:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ed7c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268

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

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.88-g71df7bb #8
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d89f7d00 ffffffff81d95f19 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810bb450 ffff8801d89f7d38
 ffffffff81da103d 0000000000000001 0000000000000000 ffff8801d93a6418
Call Trace:
 [<ffffffff81d95f19>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d95f19>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da103d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da1177>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb544>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81373b70>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81373b70>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81373b70>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81373b70>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119ae6d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b7c1c>] 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 0xffffffff838b66b6