INFO: task kworker/0:0H:11 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0H    state:D stack:26472 pid:11    tgid:11    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_requeue_work
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 nbd_queue_rq+0x857/0x1100
 blk_mq_dispatch_rq_list+0xa70/0x1910
 __blk_mq_sched_dispatch_requests+0xdcc/0x1600
 blk_mq_sched_dispatch_requests+0xd7/0x190
 blk_mq_run_hw_queue+0x348/0x4f0
 blk_mq_run_hw_queues+0x26c/0x3f0
 blk_mq_requeue_work+0x71c/0x780
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/0:0H/11:
 #0: ffff88816268e940 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90000107c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff888103b4ee98 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0
 #3: ffff888104340378 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc6/0x1100
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5439:
 #0: ffff88810d90d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
3 locks held by kworker/0:7/5727:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90005a77c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff8880120bb250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
1 lock held by udevd/13689:
 #0: ffff888103f83350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.2.6373/30008:
 #0: ffffffff8e962f38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5600 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:do_raw_spin_lock+0xa1/0x2f0
Code: 84 c0 0f 85 f3 01 00 00 41 8b 06 3d ad 4e ad de 0f 85 32 01 00 00 4c 8d 73 10 4c 89 f0 48 c1 e8 03 48 89 44 24 10 80 3c 10 00 <74> 12 4c 89 f7 e8 15 aa 8e 00 48 ba 00 00 00 00 00 fc ff df 4c 89
RSP: 0018:ffffc9000494f760 EFLAGS: 00000046
RAX: 1ffffffff34cd020 RBX: ffffffff9a6680f0 RCX: 0000000080000003
RDX: dffffc0000000000 RSI: ffffffff8e219ba1 RDI: ffffffff9a6680f0
RBP: ffffc9000494f808 R08: ffffffff84bca1cf R09: ffffffff9a668108
R10: dffffc0000000000 R11: ffffffff817652a0 R12: 1ffff92000929ef0
R13: dffffc0000000000 R14: ffffffff9a668100 R15: dffffc0000000000
FS:  000055558a950540(0000) GS:ffff88818dc8f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd29d3e8158 CR3: 000000010eae0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_lock_irqsave+0x4c/0x60
 debug_object_assert_init+0x7f/0x3b0
 hrtimer_start_range_ns+0x3f/0xed0
 finish_task_switch+0x3cd/0xbe0
 __schedule+0x17bc/0x5680
 schedule+0x164/0x360
 do_nanosleep+0x1c2/0x620
 hrtimer_nanosleep+0x18f/0x3a0
 __se_sys_clock_nanosleep+0x35b/0x3b0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3fff357f57
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd993ce720 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000055558a950540 RCX: 00007f3fff357f57
RDX: 00007ffd993ce760 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd993cec40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffd993ce79c R14: 00007ffd993ce830 R15: 0000000000000000
 </TASK>
