INFO: task syz-executor:7668 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:21832 pid:7668  tgid:7668  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: 0033:0x7f45ce18ff17
RSP: 002b:00007fff653cd0d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f45ce211c05 RCX: 00007f45ce18ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff653cd190
RBP: 00007fff653cd190 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff653ce220
R13: 00007f45ce211c05 R14: 00000000000282cb R15: 00007fff653ce260
 </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/u9:7/1093:
2 locks held by kworker/u9:9/1098:
 #0: ffff8881000e3948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006f97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5673:
 #0: ffff888020f070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u8:3/5872:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffff88804b025918 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30
1 lock held by syz-executor/7668:
 #0: ffff8880374940e0 (&type->s_umount_key#76){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz-executor/10794:
 #0: ffff88803a2be0e0 (&type->s_umount_key#69){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz.5.761/12198:
 #0: ffff8880374940e0 (&type->s_umount_key#76){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/12238:
 #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz.2.795/12433:
 #0: ffff8880374940e0 (&type->s_umount_key#76){++++}-{4:4}, at: super_lock+0x25c/0x3b0

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

NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5783 Comm: syz-executor 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_check_range+0x9f/0x2c0
Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 de 01 00 00 49 ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd
RSP: 0018:ffffc90002f9fb00 EFLAGS: 00000246
RAX: ffffc90002f9fb01 RBX: ffffffffffffffff RCX: ffffffff895847ba
RDX: 0000000000000000 RSI: 0000000000000028 RDI: ffffc90002f9fd70
RBP: ffffc90002f9fc90 R08: ffffc90002f9fd97 R09: 1ffff920005f3fb2
R10: dffffc0000000000 R11: fffff520005f3fb2 R12: 0000000000000005
R13: ffff88801fa30600 R14: fffff520005f3fb3 R15: 1ffff920005f3fae
FS:  0000555573084500(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557cab55c8 CR3: 00000000244e8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __asan_memcpy+0x29/0x70
 sock_read_iter+0xfa/0x2f0
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cae18d5bd
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d a1 af 20 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffc1412db88 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cae18d5bd
RDX: 0000000000000004 RSI: 00007ffc1412db9c RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000002e5bdbc5 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc1412dfb0
R13: 0000000000000004 R14: 00007ffc1412db9c R15: 00007ffc1412dc30
 </TASK>
