INFO: task kworker/1:0H:25 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0H    state:D stack:28760 pid:25    tgid:25    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_timeout_work
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0xc3/0x2c0
 wait_for_completion+0x2cc/0x5e0
 __synchronize_srcu+0x249/0x300
 blk_mq_timeout_work+0x1a0/0x3f0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task kworker/1:1H:568 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1H    state:D stack:26192 pid:568   tgid:568   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:
2 locks held by kworker/1:0H/25:
 #0: ffff8881026ba940 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900001f7c40 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
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/1:1H/568:
 #0: ffff8881026ba940 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900042d7c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff888166bb9818 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0
 #3: ffff8881c4e251f8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc6/0x1100
2 locks held by getty/5628:
 #0: ffff8881157800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
3 locks held by kworker/1:4/583:
 #0: ffff88823c63aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150
 #1: ffff88823c624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: __queue_work+0x1a1/0xfc0
1 lock held by udevd/10856:
 #0: ffff888169ff8350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by kworker/0:2/14077:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc9002281fc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff888107798230 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
5 locks held by syz.5.23731/16534:

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

NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5239 Comm: klogd 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:asm_sysvec_apic_timer_interrupt+0x0/0x20
Code: c6 19 b3 0a e9 81 06 00 00 90 f3 0f 1e fa 0f 01 ca fc 6a ff e8 31 05 00 00 48 89 c4 48 89 e7 e8 d6 18 b3 0a e9 61 06 00 00 90 <f3> 0f 1e fa 0f 01 ca fc 6a ff e8 11 05 00 00 48 89 c4 48 89 e7 e8
RSP: 0000:ffffc90006b8fe38 EFLAGS: 00000002
RAX: 00000000001d7c6e RBX: 0000000000000004 RCX: 0000000080000100
RDX: 0000000000000000 RSI: ffffffff8dfb64d9 RDI: ffffffff8c27f000
RBP: ffffffff8e60a0c0 R08: ffffffff903215b7 R09: 1ffffffff20642b6
R10: dffffc0000000000 R11: fffffbfff20642b7 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88817385ca00 R15: dffffc0000000000
FS:  00007fe0a7a05500(0000) GS:ffff88818dc45000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f053e51aff8 CR3: 000000010d2d1000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
RIP: 0010:handle_softirqs+0x160/0x840
Code: 89 6c 24 20 0f b7 db 48 c7 c7 00 29 cb 8b e8 c7 93 2b 0a 65 66 c7 05 85 f2 b5 11 00 00 e8 c8 79 45 00 fb 48 c7 c5 c0 a0 60 8e <b8> ff ff ff ff 0f bc c3 41 89 c6 41 ff c6 0f 84 09 04 00 00 89 5c
RSP: 0000:ffffc90006b8fe60 EFLAGS: 00000202
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0x57/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x7fe0a7aec31e
Code: e8 79 d4 ff ff 41 89 c7 85 c0 0f 88 c7 03 00 00 83 7c 24 24 00 0f 84 e3 02 00 00 44 89 f9 44 89 ea e9 18 01 00 00 41 8b 14 24 <83> fa 2f 77 10 89 d0 83 c2 08 49 03 44 24 10 41 89 14 24 eb 0e 49
RSP: 002b:00007fff825a43e0 EFLAGS: 00000213
RAX: 00007fe0a7aec31a RBX: 0000000000000073 RCX: 00007fe0a7aec5de
RDX: 0000000000000018 RSI: 00007fe0a7cf5212 RDI: 0000564cc6a96910
RBP: 0000564cc6a96910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000000 R12: 00007fff825a49e8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
