INFO: task syz-executor:5854 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:17896 pid:5854  tgid:5854  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: 0033:0x7fd27b78fed7
RSP: 002b:00007ffc8af7cf08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd27b811c05 RCX: 00007fd27b78fed7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc8af7cfc0
RBP: 00007ffc8af7cfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc8af7e050
R13: 00007fd27b811c05 R14: 000000000002c486 R15: 00007ffc8af7e090
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u10:4/156:
 #0: ffff8881000e5948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000250fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5678:
 #0: ffff88810636d0a0 (&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/5854:
 #0: ffff88810834c0e0 (&type->s_umount_key#61){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
3 locks held by kworker/u11:5/5860:
 #0: ffff888106a2e948 ((wq_completion)hci4){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000384fbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888111968dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
5 locks held by kworker/1:6/5954:
 #0: ffff888104aad548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900043cfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888021d94198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888021d97518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b8/0x4a20
 #4: ffff888021c70768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e5/0x4a20
3 locks held by bch-rebalance/l/8057:
1 lock held by syz.1.479/8357:
 #0: ffff88810834c0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.533/8623:
 #0: ffff88810834c0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0

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

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+0x439/0x7d0
 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: 8057 Comm: bch-rebalance/l 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:kasan_save_alloc_info+0x14/0x50
Code: 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 56 53 49 89 f6 48 63 87 bc 00 00 00 48 85 c0 <0f> 94 c1 49 01 c6 0f 94 c0 08 c8 74 09 5b 41 5e e9 07 14 5a 09 cc
RSP: 0018:ffffc90002c7f0c8 EFLAGS: 00000206
RAX: 0000000000000800 RBX: ffff88813040c000 RCX: 0000000000000000
RDX: 0000000000002900 RSI: ffff88813040c000 RDI: ffff88801a442000
RBP: 0000000000002900 R08: 0000000000000006 R09: 0000000000000002
R10: ffffed10260818da R11: 0000000000000000 R12: 0000000000000800
R13: ffff88813040c000 R14: ffff88813040c000 R15: 00000000000006d0
FS:  0000000000000000(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ded974c00 CR3: 0000000100af4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 bch2_move_extent+0x3ac/0x1bb0
 do_rebalance_extent+0x8f0/0x1fe0
 bch2_rebalance_thread+0x126a/0x1f80
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
