INFO: task syz-executor.5:1842 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D25008  1842      1 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:770
 vfs_open+0x105/0x230 fs/open.c:884
 do_last fs/namei.c:3455 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3597
 do_filp_open+0x1a1/0x280 fs/namei.c:3631
 do_sys_open+0x2ca/0x590 fs/open.c:1077
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
INFO: task syz-executor.1:1851 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D25008  1851      1 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:770
 vfs_open+0x105/0x230 fs/open.c:884
 do_last fs/namei.c:3455 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3597
 do_filp_open+0x1a1/0x280 fs/namei.c:3631
 do_sys_open+0x2ca/0x590 fs/open.c:1077
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
INFO: task syz-executor.4:1863 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D25128  1863      1 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:770
 vfs_open+0x105/0x230 fs/open.c:884
 do_last fs/namei.c:3455 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3597
 do_filp_open+0x1a1/0x280 fs/namei.c:3631
 do_sys_open+0x2ca/0x590 fs/open.c:1077
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
INFO: task syz-executor.3:14782 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D26848 14782   1847 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
INFO: task syz-executor.3:14798 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D29952 14798   1847 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
INFO: task syz-executor.0:14794 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29152 14794   4608 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
 loop_reread_partitions+0x7f/0x90 drivers/block/loop.c:614
 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183
INFO: task blkid:14799 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D29248 14799    292 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:770
 vfs_open+0x105/0x230 fs/open.c:884
 do_last fs/namei.c:3455 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3597
 do_filp_open+0x1a1/0x280 fs/namei.c:3631
 do_sys_open+0x2ca/0x590 fs/open.c:1077
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
INFO: task blkid:14800 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D28928 14800    291 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:770
 vfs_open+0x105/0x230 fs/open.c:884
 do_last fs/namei.c:3455 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3597
 do_filp_open+0x1a1/0x280 fs/namei.c:3631
 do_sys_open+0x2ca/0x590 fs/open.c:1077
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<000000003280aa4b>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1759:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000eb40aecb>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000360b9572>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.5/1842:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000d8518925>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
2 locks held by syz-executor.1/1851:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000d8518925>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<000000001fcc45e1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
2 locks held by syz-executor.4/1863:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000d8518925>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<000000001fcc45e1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
1 lock held by syz-executor.3/14782:
 #0:  (loop_index_mutex){+.+.}, at: [<00000000abfed720>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982
2 locks held by syz-executor.3/14798:
 #0:  (loop_index_mutex){+.+.}, at: [<00000000abfed720>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982
 #1:  (&lo->lo_ctl_mutex#2){+.+.}, at: [<00000000b2c86839>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996
2 locks held by syz-executor.0/14794:
 #0:  (&lo->lo_ctl_mutex/1){+.+.}, at: [<000000008d5b24f1>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404
 #1:  (&bdev->bd_mutex){+.+.}, at: [<00000000db0afbcc>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
2 locks held by blkid/14799:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000d8518925>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<000000001fcc45e1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
2 locks held by blkid/14800:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000d8518925>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<000000001fcc45e1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.134+ #19
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xca/0x134 lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff85883903