INFO: task kworker/1:1H:1135 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:25632 pid:1135  tgid:1135  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_run_work_fn
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 nbd_queue_rq+0x96f/0xff0
 blk_mq_dispatch_rq_list+0x499/0x1990
 __blk_mq_sched_dispatch_requests+0xd36/0x1580
 blk_mq_sched_dispatch_requests+0xd7/0x190
 blk_mq_run_work_fn+0x16c/0x300
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by kworker/1:1H/1135: 4, on CPU#1:
 #0: ffff888103e9fd40 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90007187c40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88810abc8898 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_work_fn+0x144/0x300
 #3: ffff88810ad08178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc1/0xff0
locks held by getty/5419: 2, on CPU#1:
 #0: ffff8881116590a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by kworker/1:15/6904: 3, on CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900046dfc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88816c3ca250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0
locks held by udevd/21294: 1, on CPU#1:
 #0: ffff88810ac3c350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70
locks held by kworker/1:14/26625: 3, on CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000398fc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff90253220 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x209/0x780
locks held by kworker/1:23/26626: 3, last CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000419fc40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902d3400 (nf_conntrack_mutex){+.+.}-{4:4}, at: nf_ct_iterate_cleanup+0x3f/0x500
locks held by syz.4.5086/26889: 1, on CPU#1:
 #0: ffffffff90253220 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00
locks held by syz.1.5087/26886: 2, last CPU#1:
 #0: ffffffff90253220 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc1d/0x1c30
 #1: ffffffff8ed62ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
locks held by syz.1.5087/26888: 4, last CPU#0:
 #0: ffff8881a8995c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0
 #1: ffffffff902c2188 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: nl80211_netlink_notify+0x75/0x860
 #3: ffff888121028298 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x466/0xa10
locks held by syz.3.5088/26887: 2, on CPU#1:
 #0: ffff8881a8b4a640 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0
 #1: ffffffff8ed62ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770

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

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+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 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: 26888 Comm: syz.1.5087 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:native_apic_msr_write+0x39/0x50
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc 89 f6 31 d2 e9 a6 ba a6 03 66 0f 1f 44 00
RSP: 0018:ffffc90000007e50 EFLAGS: 00000046
RAX: 000000000000000f RBX: ffff888121023c80 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000000000f RDI: 0000000000000838
RBP: ffffc90000007f08 R08: 0000000000000100 R09: 0000000000000001
R10: 0000000000000003 R11: ffffffff81754510 R12: ffffffff81754510
R13: 1ffff11024204799 R14: 0000000000000000 R15: ffff888121023ccc
FS:  00007f96054b96c0(0000) GS:ffff88818d6cd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001b9a2c000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lapic_next_event+0x11/0x20
 clockevents_program_event+0x44e/0x630
 hrtimer_run_softirq+0x255/0x2e0
 handle_softirqs+0x226/0x860
 do_softirq+0x77/0xd0
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x140
 cfg80211_mlme_unregister_socket+0x2c8/0x650
 nl80211_netlink_notify+0x35d/0x860
 notifier_call_chain+0x1a5/0x3d0
 blocking_notifier_call_chain+0x6a/0x90
 netlink_release+0x11fb/0x1a80
 __sock_release+0xa0/0x1f0
 sock_close+0x1c/0x30
 __fput+0x418/0xa50
 fput_close_sync+0x11f/0x240
 __x64_sys_close+0x7e/0x110
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f960455e98e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f96054b7f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f96054b96c0 RCX: 00007f960455e98e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000012
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9604826128 R14: 00007f9604826090 R15: 00007fff7b755d38
 </TASK>
