INFO: task syz.7.3608:21082 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.7.3608      state:D stack:24344 pid:21082 tgid:21081 ppid:15267  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 super_lock+0x1e0/0x3d0
 __iterate_supers+0x126/0x250
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa698f9cdd9
RSP: 002b:00007fa699e56028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fa699215fa0 RCX: 00007fa698f9cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa699215fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa699216038 R14: 00007fa699215fa0 R15: 00007ffd7d49b8e8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff8881052b6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900000e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff88816c1f61d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5438:
 #0: ffff888176c480a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
3 locks held by kworker/0:9/11745:
1 lock held by syz.0.2335/15518:
 #0: ffff8881167b40d8 (&type->s_umount_key#132/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0
2 locks held by syz.9.4515/24571:

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

NMI backtrace for cpu 1
CPU: 1 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/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 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: 11745 Comm: kworker/0:9 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:asm_sysvec_apic_timer_interrupt+0x0/0x20
Code: b6 99 a8 0a e9 81 06 00 00 90 f3 0f 1e fa 0f 1f 00 fc 6a ff e8 31 05 00 00 48 89 c4 48 89 e7 e8 c6 98 a8 0a e9 61 06 00 00 90 <f3> 0f 1e fa 0f 1f 00 fc 6a ff e8 11 05 00 00 48 89 c4 48 89 e7 e8
RSP: 0018:ffffc90004307278 EFLAGS: 00000087
RAX: ffffffff81a49855 RBX: ffffffff81a496cf RCX: 0000000000100000
RDX: ffffc9002827d000 RSI: 0000000000051f80 RDI: ffffffff8e94f1a0
RBP: ffffc90004307350 R08: ffffffff9030b3f7 R09: 1ffffffff206167e
R10: dffffc0000000000 R11: fffffbfff206167f R12: 0000000000000000
R13: 000000000000004d R14: 0000000000000200 R15: 1ffff92000860e58
FS:  0000000000000000(0000) GS:ffff88818dc8d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f696379c440 CR3: 000000011242e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
RIP: 0010:vprintk_emit+0x45d/0x560
Code: 0f 84 44 ff ff ff e8 92 29 21 00 fb eb 44 e8 8a 29 21 00 e8 d5 1c 04 0a 4d 85 f6 74 94 e8 7b 29 21 00 fb 48 c7 c7 a0 f1 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18
RSP: 0018:ffffc900043072a0 EFLAGS: 00000287
 dev_vprintk_emit+0x355/0x420
 dev_printk_emit+0xee/0x140
 _dev_info+0x11e/0x180
 announce_device+0xa1/0x2c0
 usb_new_device+0x4d8/0x16f0
 hub_event+0x2a1c/0x4f30
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
