INFO: task syz.8.3339:20969 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.3339      state:D stack:27368 pid:20969 tgid:20968 ppid:20618  task_flags:0x400140 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/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f718b18d510
RSP: 002b:00007f718c0c0b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f718b18d510
RDX: 0000000000000002 RSI: 00007f718c0c0c10 RDI: 00000000ffffff9c
RBP: 00007f718c0c0c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f718b3d6038 R14: 00007f718b3d5fa0 R15: 00007fff030da628
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e33c560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5678:
 #0: ffff88810daa00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900025482f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by syz-executor/6297:
6 locks held by kworker/0:6/17708:
 #0: ffff888104aee148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003d5fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8880247a8198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888024af9198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88813098f160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #5: ffffffff8e1e2790 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0
1 lock held by syz.8.3339/20969:
 #0: ffff8880247a8198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760
3 locks held by syz.9.3971/25337:

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

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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x47f/0x820
 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: 5878 Comm: kworker/u8:3 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: bat_events batadv_mcast_mla_update
RIP: 0010:asm_sysvec_apic_timer_interrupt+0x0/0x20
Code: 36 76 81 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 46 75 81 0a e9 41 06 00 00 90 <f3> 0f 1e fa 0f 1f 00 fc 6a ff e8 f1 04 00 00 48 89 c4 48 89 e7 e8
RSP: 0018:ffffc9000470f618 EFLAGS: 00000093
RAX: ffffffff81a012d5 RBX: ffffffff81a0112e RCX: ffff888022a73a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e330580
RBP: ffffc9000470f750 R08: ffffffff8fc3c837 R09: 1ffffffff1f87906
R10: dffffc0000000000 R11: fffffbfff1f87907 R12: 0000000000000000
R13: 000000000000004f R14: 0000000000000200 R15: 1ffff920008e1ecc
FS:  0000000000000000(0000) GS:ffff8881a39f1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75ea6cc000 CR3: 0000000024d1e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
RIP: 0010:vprintk_emit+0x49d/0x590
Code: 0f 84 34 ff ff ff e8 52 99 1f 00 fb eb 44 e8 4a 99 1f 00 e8 45 7f e1 09 4d 85 f6 74 94 e8 3b 99 1f 00 fb 48 c7 c7 80 05 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 6b 3b
RSP: 0018:ffffc9000470f640 EFLAGS: 00000293
 _printk+0xcf/0x120
 batadv_mcast_mla_update+0x34b4/0x3640
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x47f/0x820
 ret_from_fork_asm+0x1a/0x30
 </TASK>
