INFO: task syz-executor:7160 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:18856 pid:7160  tgid:7160  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: 0033:0x7fe69f58ff57
RSP: 002b:00007ffe78932ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe69f611c2d RCX: 00007fe69f58ff57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe78932b90
RBP: 00007ffe78932b90 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe78933c20
R13: 00007fe69f611c2d R14: 0000000000020078 R15: 00007ffe78933c60
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u9:0/26:
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/u9:3/2259:
 #0: ffff888101284948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000b0a7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5676:
 #0: ffff888020add0a0 (&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/7160:
 #0: ffff88802a6c00e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz.6.457/8156:
 #0: ffff88802a6c00e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.465/8187:
 #0: ffff88802a6c00e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
4 locks held by syz.5.806/10107:
2 locks held by syz.7.807/10109:

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

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+0x439/0x7d0
 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: 10107 Comm: syz.5.806 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:format_decode+0x3b2/0xe30
Code: 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 8b 06 00 00 66 41 c7 04 24 ff ff 48 89 e8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 9a 06 00 00 <0f> b6 5d 00 bf 2e 00 00 00 89 de e8 4e 27 49 f6 83 fb 2e 0f 84 44
RSP: 0018:ffffc90003bbe6f0 EFLAGS: 00000297
RAX: 0000000000000005 RBX: ffffc90003bbe79b RCX: 000000008b8b8101
RDX: dffffc0000000000 RSI: 00000000000039bf RDI: 00000000000039c0
RBP: ffffffff8b8b8141 R08: ffff888107ab8000 R09: 0000000000000002
R10: 0000000000000025 R11: 0000000000000002 R12: ffffc90003bbe79a
R13: 1ffff92000777cf3 R14: 0000000000000063 R15: ffffffff8b8b8141
FS:  00007f78d5ff66c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34411ff8 CR3: 0000000026fd6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 vsnprintf+0x102/0xf00
 snprintf+0xda/0x120
 info_print_prefix+0x1e1/0x310
 record_print_text+0x154/0x420
 printk_get_next_message+0x26d/0x7b0
 console_flush_all+0x4ca/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 __nla_validate_parse+0x1719/0x2d40
 __nla_parse+0x40/0x60
 genl_family_rcv_msg_attrs_parse+0x1c9/0x2a0
 genl_family_rcv_msg_doit+0xb8/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f78d7d8ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f78d5ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f78d7fd5fa0 RCX: 00007f78d7d8ec29
RDX: 0000000000000084 RSI: 0000200000000a00 RDI: 000000000000000c
RBP: 00007f78d7e11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78d7fd6038 R14: 00007f78d7fd5fa0 R15: 00007ffc415a5398
 </TASK>
