INFO: task syz-executor.0:2081 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #23
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D24456  2081      1 0x20020004
 ffff8801d11faf80 ffff8801d0a8c780 ffff8801d525f900 ffff8801c5c517c0
 ffff8801db721018 ffff8801b3b07658 ffffffff828075c2 0000000000000000
 ffff8801d11fb830 ffffed003a23f705 00ff8801d11faf80 ffff8801db7218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828094a3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff8280b51d>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8280b51d>] mutex_lock_nested+0x38d/0x900 kernel/locking/mutex.c:621
 [<ffffffff815c89bc>] __blkdev_get+0x10c/0xd60 fs/block_dev.c:1268
 [<ffffffff815cb7ea>] blkdev_get+0x2da/0x920 fs/block_dev.c:1416
 [<ffffffff815cc045>] blkdev_open+0x1a5/0x250 fs/block_dev.c:1571
 [<ffffffff81501e3f>] do_dentry_open+0x3ef/0xc90 fs/open.c:766
 [<ffffffff8150576c>] vfs_open+0x11c/0x210 fs/open.c:879
 [<ffffffff8153c542>] do_last fs/namei.c:3410 [inline]
 [<ffffffff8153c542>] path_openat+0x542/0x2790 fs/namei.c:3534
 [<ffffffff81541617>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8150617d>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8161882a>] C_SYSC_open fs/compat.c:1081 [inline]
 [<ffffffff8161882a>] compat_SyS_open+0x2a/0x40 fs/compat.c:1079
 [<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
 [<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
 [<ffffffff82818de0>] 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/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2030:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor.0/2081:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815c89bc>] __blkdev_get+0x10c/0xd60 fs/block_dev.c:1268
2 locks held by syz-executor.5/2083:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815c89bc>] __blkdev_get+0x10c/0xd60 fs/block_dev.c:1268
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81de129b>] lo_open+0x1b/0xa0 drivers/block/loop.c:1589
2 locks held by syz-executor.3/2085:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815c89bc>] __blkdev_get+0x10c/0xd60 fs/block_dev.c:1268
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81de129b>] lo_open+0x1b/0xa0 drivers/block/loop.c:1589
2 locks held by syz-executor.2/2086:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815c89bc>] __blkdev_get+0x10c/0xd60 fs/block_dev.c:1268
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81de129b>] lo_open+0x1b/0xa0 drivers/block/loop.c:1589
2 locks held by syz-executor.1/6821:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff81de73ac>] lo_ioctl+0x8c/0x1910 drivers/block/loop.c:1372
 #1:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81b0b9fe>] blkdev_reread_part+0x1e/0x40 block/ioctl.c:189
1 lock held by syz-executor.1/6832:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff81de73ac>] lo_ioctl+0x8c/0x1910 drivers/block/loop.c:1372
2 locks held by syz-executor.4/6828:
 #0:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81de91da>] loop_control_ioctl+0x7a/0x300 drivers/block/loop.c:1941
 #1:  (&lo->lo_ctl_mutex#2){+.+.+.}, at: [<ffffffff81de92e6>] loop_control_ioctl+0x186/0x300 drivers/block/loop.c:1955
1 lock held by syz-executor.4/6837:
 #0:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81de91da>] loop_control_ioctl+0x7a/0x300 drivers/block/loop.c:1941
2 locks held by blkid/6826:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815c89bc>] __blkdev_get+0x10c/0xd60 fs/block_dev.c:1268
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81de129b>] lo_open+0x1b/0xa0 drivers/block/loop.c:1589

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #23
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4df89>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4df1c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810984b4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131c65d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c65d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c65d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c65d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] 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
CPU: 1 PID: 2044 Comm: syz-fuzzer Not tainted 4.9.141+ #23
task: ffff8801d09f5f00 task.stack: ffff8801cf788000
RIP: 0033:[<000000000041debf>] 
c [<000000000041debf>] 0x41debf
RSP: 002b:000000c420033e80  EFLAGS: 00000293
RAX: 000000c420000000 RBX: 000000c41fe9bf1b RCX: 0000000000000000
RDX: 000000c42cec0000 RSI: 000000c422c81c80 RDI: 0000000000000000
RBP: 000000c420033f18 R08: 0000000000000000 R09: 0000000000c2e800
R10: 0000000000000040 R11: 000000c422c81c80 R12: 000000c422994800
R13: 0000000000000019 R14: 000000000045b6a0 R15: 0000000000000000
FS:  000000c4200283e8(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1f50a13750 CR3: 00000001d1187000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400