INFO: task syz.0.760:9957 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.760       state:D stack:28624 pid:9957  tgid:9956  ppid:5860   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 bdev_open+0xe0/0xd30
 bdev_file_open_by_dev+0x1be/0x240
 setup_bdev_super+0x5a/0x5b0
 get_tree_bdev_flags+0x366/0x4d0
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb59dd8ec29
RSP: 002b:00007fb59eb39038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb59dfd5fa0 RCX: 00007fb59dd8ec29
RDX: 0000200000000040 RSI: 0000200000000000 RDI: 00002000000000c0
RBP: 00007fb59de11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb59dfd6038 R14: 00007fb59dfd5fa0 R15: 00007ffd42866db8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
6 locks held by kworker/0:2/2207:
 #0: ffff88801bb91d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000a8d7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888022c0c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888022c0e518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b8/0x4a20
 #4: ffff888022c3cb68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e5/0x4a20
 #5: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
2 locks held by getty/5680:
 #0: ffff8880242b70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900027f82f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/5853:
 #0: ffff888108f1a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by syz.0.760/9957:
 #0: ffff888039cce0e0 (&type->s_umount_key#104/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970
 #1: ffff888108f1a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by dhcpcd/12871:
 #0: ffff88804136c258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 2207 Comm: kworker/0:2 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
Workqueue: usb_hub_wq hub_event
RIP: 0010:__lock_acquire+0xaa6/0xd20
Code: 06 0e 00 75 19 90 48 c7 c7 bb 88 ba 8d 48 c7 c6 82 d5 a9 8d e8 9b de e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 <0f> 84 6a 01 00 00 4c 89 f6 89 ea 4c 89 f9 e8 17 38 00 00 85 c0 0f
RSP: 0018:ffffc9000a8d70f0 EFLAGS: 00000082
RAX: ffffffff93499ba8 RBX: 0000000000000003 RCX: 000000004435ee8a
RDX: 00000000c3b80388 RSI: 00000000c1578153 RDI: ffff88801f060000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81a02614
R10: dffffc0000000000 R11: fffffbfff1f474e7 R12: 00000000a64569e5
R13: ffff88801f060af0 R14: ffff88801f060b68 R15: 346a5c374435ee8a
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562743256600 CR3: 0000000023a16000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 vprintk_emit+0x5a7/0x7a0
 dev_vprintk_emit+0x337/0x3f0
 dev_printk_emit+0xe0/0x130
 _dev_info+0x10a/0x160
 usb_new_device+0x4ef/0x16f0
 hub_event+0x2958/0x4a20
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
