INFO: task syz-executor:5851 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20648 pid:5851  tgid:5851  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 __writeback_inodes_sb_nr+0x1f6/0x250
 sync_filesystem+0xa3/0x230
 generic_shutdown_super+0x6f/0x2c0
 bch2_kill_sb+0x41/0x50
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f233c18ff17
RSP: 002b:00007ffd3674e2a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f233c211c05 RCX: 00007f233c18ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd3674e360
RBP: 00007ffd3674e360 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd3674f3f0
R13: 00007f233c211c05 R14: 000000000001613d R15: 00007ffd3674f430
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u10:3/157:
2 locks held by kworker/1:2/792:
3 locks held by kworker/0:2/973:
 #0: ffff888100ebdd48 ((wq_completion)pm){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006af7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888108d34198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
2 locks held by kworker/u9:4/995:
 #0: ffff88801b36e948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006c47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5677:
 #0: ffff88810d5740a0 (&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
1 lock held by syz-executor/5851:
 #0: ffff8880313040e0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
5 locks held by kworker/1:4/5885:
 #0: ffff88801bf35948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000447fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888108cc4198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888030886198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88802985c160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
4 locks held by udevd/6179:
 #0: ffff88812db762f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10
 #1: ffff888111f76088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0
 #2: ffff8881296f0c38 (kn->active#30){.+.+}-{0:0}, at: kernfs_seq_start+0x75/0x3c0
 #3: ffff888030886198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0
2 locks held by bch-copygc/loop/6539:
 #0: ffff888032b04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220
 #1: ffff888032b26710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0

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

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:validate_chain+0x1e1/0x2140
Code: cc 48 ff cb f7 c1 00 60 00 00 74 c8 e9 8d 00 00 00 48 c7 c7 90 af 00 8e 4c 89 fe e8 99 bc 61 03 48 8b 14 24 eb c9 48 8b 48 18 <4c> 39 f9 0f 84 b2 00 00 00 48 8b 40 08 48 85 c0 0f 84 c2 fe ff ff
RSP: 0018:ffffc900001e09b8 EFLAGS: 00000046
RAX: ffffffff93a87a30 RBX: 000000000003b472 RCX: 9ffed2a8eca3d5cc
RDX: 0000000000000000 RSI: ffff888100038af0 RDI: ffff888100038000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8190cef7
R10: dffffc0000000000 R11: ffffffff81adf0d0 R12: 0000000000000001
R13: ffff888100038af0 R14: ffff888100038af0 R15: 9ffed2a8eca3d5cc
FS:  0000000000000000(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32e20ff8 CR3: 00000000280d2000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 try_to_wake_up+0x67/0x12b0
 hrtimer_wakeup+0x4e/0x60
 __hrtimer_run_queues+0x52c/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
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 73 67 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: 547f8936a0b26100 RBX: ffffffff819683c8 RCX: 547f8936a0b26100
RDX: 0000000000000001 RSI: ffffffff8d9b8254 RDI: ffffffff8be33900
RBP: ffffc90000177f20 R08: ffff888136632f9b R09: 1ffff11026cc65f3
R10: dffffc0000000000 R11: ffffed1026cc65f4 R12: ffffffff8fa39030
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11020007000
 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>
