EXT4-fs (sda1): re-mounted. Opts: (null)
INFO: task syz-executor.5:2131 blocked for more than 140 seconds.
      Not tainted 4.9.170+ #48
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D25144  2131      1 0x00000004
 ffff8801cea8df00 ffff8801a2d81600 ffff8801db721000 ffff8801a7488000
 ffff8801db721018 ffff8801b047f988 ffffffff82801a4e 0000000000000000
 ffffffff830c1d40 00ff8801b047f9b0 ffff8801db7218f0 1ffff1003608ff20
Call Trace:
 [<00000000abf52634>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<00000000cd0e88fd>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<000000006e3169ca>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<000000006e3169ca>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<00000000fafecd62>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
 [<0000000002da7b4b>] loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:638
 [<00000000217b3e7c>] loop_clr_fd+0x7dd/0xa60 drivers/block/loop.c:1082
 [<00000000014b5b79>] lo_ioctl+0x7b6/0x1a10 drivers/block/loop.c:1415
 [<00000000e884bc66>] __blkdev_driver_ioctl block/ioctl.c:294 [inline]
 [<00000000e884bc66>] blkdev_ioctl+0xe14/0x19e0 block/ioctl.c:590
 [<000000002c03fe24>] block_ioctl+0xde/0x120 fs/block_dev.c:1696
 [<000000002635defa>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<000000002635defa>] file_ioctl fs/ioctl.c:493 [inline]
 [<000000002635defa>] do_vfs_ioctl+0xb87/0x11d0 fs/ioctl.c:677
 [<000000003e42cc57>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<000000003e42cc57>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<000000003c47dd85>] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285
 [<000000000474c7f8>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<000000009604bca5>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<000000009604bca5>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<00000000de139a72>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339
1 lock held by rsyslogd/1917:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<00000000fadcf351>] __fdget_pos+0xa8/0xd0 fs/file.c:782
2 locks held by getty/2044:
 #0:  (&tty->ldisc_sem){++++++}, at: [<00000000742c9747>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<0000000024599f7c>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.5/2131:
 #0:  (loop_ctl_mutex/1){+.+.+.}, at: [<000000000fd1f37c>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405
 #1:  (&bdev->bd_mutex){+.+.+.}, at: [<00000000fafecd62>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
3 locks held by syz-executor.1/6447:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<00000000fbf3afc6>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587
 #1:  (loop_index_mutex){+.+.+.}, at: [<000000007a2f5acf>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664
 #2:  (loop_ctl_mutex#2){+.+.+.}, at: [<000000001a576019>] __lo_release drivers/block/loop.c:1642 [inline]
 #2:  (loop_ctl_mutex#2){+.+.+.}, at: [<000000001a576019>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665
1 lock held by syz-executor.4/6467:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<00000000208fcfbf>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
2 locks held by blkid/6461:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<00000000208fcfbf>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
 #1:  (loop_index_mutex){+.+.+.}, at: [<00000000a8c6b98a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622
1 lock held by blkid/6462:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<00000000208fcfbf>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.170+ #48
 ffff8801d98d7cc8 ffffffff81b4fb21 0000000000000000 0000000000000000
 0000000000000000 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b5adbc 0000000000000000 0000000000000000 0000000000000000
Call Trace:
 [<000000003a8c7011>] __dump_stack lib/dump_stack.c:15 [inline]
 [<000000003a8c7011>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<00000000131268d9>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<000000006c5b0b98>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<00000000dc40d9cb>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<00000000751fccec>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<00000000751fccec>] check_hung_task kernel/hung_task.c:126 [inline]
 [<00000000751fccec>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
 [<00000000751fccec>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
 [<000000007750e678>] kthread+0x278/0x310 kernel/kthread.c:211
 [<000000001d78ca6d>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff82810ac2