INFO: task syz.3.2379:11603 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2379      state:D stack:27632 pid:11603 tgid:11601 ppid:7596   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7bf/0x1550
 write_versions+0x95/0xe30
 nfsctl_transaction_write+0x10f/0x160
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f61dd99e0d9
RSP: 002b:00007f61de82d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f61ddc26090 RCX: 00007f61dd99e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f61dda35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f61ddc26128 R14: 00007f61ddc26090 R15: 00007ffc351689e8
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/1:0/24:
 #0: ffff88816809dd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff88810af1f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30
 #3: ffff88810af8c568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30
 #4: ffff88810af3fe60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30
 #5: ffffffff8f8d57c8 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14d/0x1810
6 locks held by kworker/1:1/31:
 #0: ffff88816809dd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90000a67c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff88810ae5f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30
 #3: ffff88817222d1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450
 #4: ffff8881722281a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450
 #5: ffff88816c7d9d78 (&dev->ctrl_urb_lock){+.+.}-{4:4}, at: em28xx_write_regs_req+0x129/0x3c0
1 lock held by khungtaskd/34:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5428:
 #0: ffff88810a2e00a0 (&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
6 locks held by kworker/1:6/5680:
 #0: ffff88816809dd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc9000706fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff88810ae571d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30
 #3: ffff88810af1c568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30
 #4: ffff88810aec5f60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30
 #5: ffff88823c63b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160
4 locks held by udevd/8078:
 #0: ffff88802c3431b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0
 #1: ffff888113917480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420
 #2: ffff88816b4c21e8 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420
 #3: ffff88817222d1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0
3 locks held by syz.3.2379/11602:
 #0: ffff888101fe00f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: 
ffff88817267c450
 (
sb_writers#43){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8dd80 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10
3 locks held by syz.3.2379/11603:
 #0: ffff888171afecf0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff88817267c450 (sb_writers#43){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8dd80 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30
2 locks held by syz-executor/12007:
 #0: ffff8881a84b80d8 (&type->s_umount_key#134){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffffffff8ee8dd80 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 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: 5680 Comm: kworker/1:6 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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:do_raw_spin_unlock+0x59/0x210
Code: 57 01 00 00 41 81 3e ad 4e ad de 0f 85 c6 00 00 00 48 89 df be 04 00 00 00 e8 73 44 91 00 48 89 d8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 47 01 00 00 83 3b 00 0f 84 bd 00 00 00 4c 8d 73 10 4d
RSP: 0018:ffffc9000706e678 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffffffff8eb4bee0 RCX: ffffffff81a35cbd
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8eb4bee0
RBP: ffffc9000706e7d0 R08: ffffffff8eb4bee3 R09: 1ffffffff1d697dc
R10: dffffc0000000000 R11: fffffbfff1d697dd R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff8eb4bee4 R15: ffffffff8f46efa0
FS:  0000000000000000(0000) GS:ffff8882a8f54000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffa88a9b78 CR3: 000000010a30e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_unlock+0x1e/0x50
 console_flush_all+0x66c/0xaf0
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 dev_vprintk_emit+0x338/0x400
 dev_printk_emit+0xee/0x140
 _dev_err+0x11e/0x180
 cdc_parse_cdc_header+0x49f/0x910
 wdm_probe+0x12b/0x310
 usb_probe_interface+0x653/0xc60
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x270/0x410
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c4/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7d7/0xb80
 usb_set_configuration+0x1ad8/0x2180
 usb_generic_driver_probe+0x8d/0x150
 usb_probe_device+0x1c3/0x3b0
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x270/0x410
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c4/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7d7/0xb80
 usb_new_device+0x9aa/0x1690
 hub_event+0x28e8/0x4d30
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
