INFO: task syz.4.665:8670 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.665       state:D stack:27800 pid:8670  tgid:8669  ppid:7338   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 usbdev_open+0x16e/0x760
 chrdev_open+0x4cc/0x5e0
 do_dentry_open+0x953/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f299758d550
RSP: 002b:00007f29957f5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000000a401 RCX: 00007f299758d550
RDX: 000000000000a401 RSI: 00007f29957f5c10 RDI: 00000000ffffff9c
RBP: 00007f29957f5c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f29977c6038 R14: 00007f29977c5fa0 R15: 00007ffcca3d33f8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/0:2/793:
 #0: ffff888136414f48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90004cbfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810944f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
2 locks held by getty/5675:
 #0: ffff88801b6f90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
6 locks held by kworker/1:5/5899:
 #0: ffff888136414f48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003ddfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888021777198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888021cf8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff8881076b8160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #5: ffffffff8dfe0310 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0
2 locks held by syz-executor/7401:
 #0: ffffffff8e88e408 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690
 #1: ffffffff8e13f840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
1 lock held by syz.4.665/8670:
 #0: ffff888021777198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760
1 lock held by syz.6.771/9152:
 #0: ffff888021777198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760

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

NMI backtrace for cpu 0
CPU: 0 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+0x3fc/0x770
 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: 0 Comm: swapper/1 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:pv_native_safe_halt+0x13/0x20
Code: 53 e7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d f3 86 0e 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000177de0 EFLAGS: 00000282
RAX: 85fae1afbb8bff00 RBX: ffffffff819683c8 RCX: 85fae1afbb8bff00
RDX: 0000000000000001 RSI: ffffffff8d9b77e3 RDI: ffffffff8be33680
RBP: ffffc90000177f20 R08: ffff888136632f9b R09: 1ffff11026cc65f3
R10: dffffc0000000000 R11: ffffed1026cc65f4 R12: ffffffff8fa38a30
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11020005000
FS:  0000000000000000(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056336ab60cf8 CR3: 000000002227c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 start_secondary+0x101/0x110
 common_startup_64+0x13e/0x147
 </TASK>
