INFO: task kworker/0:1H:559 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H    state:D stack:25496 pid:559   tgid:559   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:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/0:1H/559:
 #0: ffff8881626d0540 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900041a7c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff888103f2dd98 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0
 #3: ffff8881047997f8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc6/0x1100
2 locks held by getty/5629:
 #0: ffff8881789590a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/27990:
 #0: ffff8881043c5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.1.31319/4423:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 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+0xfaa/0x1000
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5803 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:clockevents_program_event+0x1b9/0x5f0
Code: 3c 24 4c 89 fe e8 a7 c9 fc ff 84 c0 0f 84 da 00 00 00 e8 5a 8e 0f 00 48 8b 44 24 40 48 89 c2 48 c1 ea 20 b9 e0 06 00 00 0f 30 <4c> 8b 64 24 10 43 c6 44 2c 04 f8 31 c0 48 c7 44 24 20 0e 36 e0 45
RSP: 0018:ffffc90000a08ec0 EFLAGS: 00000006
RAX: 000007597fbc87aa RBX: ffff88823c623e40 RCX: 00000000000006e0
RDX: 0000000000000759 RSI: 0000000000000014 RDI: 0000000000000040
RBP: ffffc90000a08f80 R08: ffffffff81b2997e R09: ffffffff9a4d55c8
R10: 0000000000000003 R11: 0000000000000000 R12: ffff88823c623e88
R13: dffffc0000000000 R14: 0000000000000004 R15: 0000029f57355e66
FS:  0000555559898500(0000) GS:ffff8882a9245000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcb6f93ce0 CR3: 000000016c363000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 __hrtimer_rearm_deferred+0x270/0x450
 __irq_exit_rcu+0x14e/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0xd6f/0x2550
Code: 00 00 83 fe 02 0f 85 b2 07 00 00 4c 89 7c 24 38 4d 8d 7e 08 4c 89 fd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 80 7c 05 00 00 <74> 08 4c 89 ff e8 17 b9 ba 00 4c 89 7c 24 68 48 89 9c 24 80 00 00
RSP: 0018:ffffc900017df878 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffffff90c6c6b3 RCX: ffffffff904a7acc
RDX: ffffffff90c6c6ae RSI: 0000000000000002 RDI: ffffffff8c27efa0
RBP: 1ffff920002fbf36 R08: 0000000000000009 R09: ffffffff8e95d020
R10: ffffc900017df9a8 R11: fffff520002fbf41 R12: ffffc900017df9a8
R13: 1ffff920002fbf35 R14: ffffc900017df9a8 R15: ffffc900017df9b0
 __unwind_start+0x5b8/0x760
 arch_stack_walk+0xe3/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x2bc/0x650
 do_getname+0x2e/0x250
 user_path_at+0x2a/0x160
 __x64_sys_umount+0xf6/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcb07b9e017
Code: a2 c7 05 dc 06 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffcb6f94338 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcb07b9e017
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcb6f943f0
RBP: 00007ffcb6f943f0 R08: 00007ffcb6f953f0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcb6f95480
R13: 00007fcb07c32120 R14: 00000000002bf4d8 R15: 00007ffcb6f954c0
 </TASK>
