INFO: task syz.2.1323:2430 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1323      state:D stack:22584 pid:2430  tgid:2428  ppid:1273   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 super_lock+0x25c/0x3b0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f621338ec29
RSP: 002b:00007f6214141038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f62135d5fa0 RCX: 00007f621338ec29
RDX: 0000000000000000 RSI: 000020000001fc80 RDI: ffffffff80000201
RBP: 00007f6213411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62135d6038 R14: 00007f62135d5fa0 R15: 00007ffc782b0068
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000c7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5669:
 #0: ffff8880265690a0 (&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
2 locks held by syz-executor/25193:
1 lock held by syz.2.1323/2430:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x25c/0x3b0
2 locks held by syz.3.1417/6054:
 #0: ffff8880339e8428 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/6564:
1 lock held by syz.2.1488/8940:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.1488/8984:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9160:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9162:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9163:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9166:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9167:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9168:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9169:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1539/9170:
 #0: ffff888011f480e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/9204:

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

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: 3 Comm: pool_workqueue_ 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:zap_class+0xe5/0x360
Code: c1 75 d7 45 8b 7d 00 41 f6 c7 fc 0f 84 e2 00 00 00 41 c1 ef 08 4e 8d 34 7d 10 93 a9 92 49 81 ff 00 00 50 00 73 30 41 0f b7 06 <25> ff 1f 00 00 48 39 c3 74 33 49 ff c7 41 8b 45 00 89 c1 c1 e9 08
RSP: 0018:ffffc90000067bc0 EFLAGS: 00000083
RAX: 00000000000028fb RBX: 0000000000000d46 RCX: 0000000000050e97
RDX: ffffffff93a69368 RSI: ffffffff93a69368 RDI: ffffffff9353f1d0
RBP: ffffffff93a897b0 R08: 0000000000000000 R09: ffffffff81aa8548
R10: dffffc0000000000 R11: fffffbfff1f474e7 R12: 0000000000034aaa
R13: ffffffff93d05af0 R14: ffffffff92b3b040 R15: 0000000000050e98
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2864722000 CR3: 0000000026998000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lockdep_unregister_key+0x1a6/0x310
 pwq_release_workfn+0x6d5/0x870
 kthread_worker_fn+0x507/0xb60
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
