INFO: task syz.6.657:11601 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.657       state:D stack:25128 pid:11601 tgid:11600 ppid:11201  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8bc318eba9
RSP: 002b:00007f8bc4065038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f8bc33d5fa0 RCX: 00007f8bc318eba9
RDX: 000000000000ee00 RSI: 0000200000000240 RDI: ffffffff80000800
RBP: 00007f8bc3211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8bc33d6038 R14: 00007f8bc33d5fa0 R15: 00007fffc7373788
 </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
3 locks held by kworker/u10:5/1090:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90007127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a788 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by dhcpcd/5592:
 #0: ffffffff8f53a788 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5677:
 #0: ffff88810fd880a0 (&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
4 locks held by syz-executor/5855:
5 locks held by kworker/u8:2/5862:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000368fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d8d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f53a788 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890
 #4: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
3 locks held by kworker/u8:4/5914:
 #0: ffff888020ac6948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000394fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a788 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
4 locks held by syz-executor/7152:
1 lock held by syz.6.657/11601:
 #0: ffff8880123f60e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.801/13000:
 #0: ffff88802ea040e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x25c/0x3b0
2 locks held by syz-executor/13508:
 #0: ffffffff8fa5b190 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f53a788 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
3 locks held by syz.3.874/13547:

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

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: 7152 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:do_raw_spin_unlock+0xd9/0x240
Code: 00 41 8b 07 65 8b 0d ba a9 02 11 39 c8 0f 85 d4 00 00 00 43 80 7c 25 00 00 74 08 4c 89 f7 e8 5e 45 85 00 49 c7 06 ff ff ff ff <42> 0f b6 44 25 00 84 c0 0f 85 29 01 00 00 41 c7 07 ff ff ff ff 48
RSP: 0018:ffffc90002e6f918 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88803dc40b88 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88803dc40b88
RBP: 1ffff11007b88172 R08: ffff88803dc40b8b R09: 1ffff11007b88171
R10: dffffc0000000000 R11: ffffed1007b88172 R12: dffffc0000000000
R13: 1ffff11007b88173 R14: ffff88803dc40b98 R15: ffff88803dc40b90
FS:  0000555569d0d500(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6899ffe00 CR3: 0000000114a0a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_unlock+0x1e/0x50
 f2fs_write_checkpoint+0xaf7/0x1df0
 kill_f2fs_super+0x2c3/0x6c0
 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: 0033:0x7f071d98fed7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffeab7cfdc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f071da11c05 RCX: 00007f071d98fed7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffeab7cfe80
RBP: 00007ffeab7cfe80 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffeab7d0f10
R13: 00007f071da11c05 R14: 00000000000270ce R15: 00007ffeab7d0f50
 </TASK>
