INFO: task syz.5.662:10396 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.662       state:D stack:25464 pid:10396 tgid:10395 ppid:10167  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6d9/0x940
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x250
 __se_sys_quotactl+0x3a7/0x9e0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5fd579cdd9
RSP: 002b:00007f5fd65f5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f5fd5a15fa0 RCX: 00007f5fd579cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102
RBP: 00007f5fd5832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5fd5a16038 R14: 00007f5fd5a15fa0 R15: 00007ffd3d3ae718
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5646:
 #0: ffff8881727340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
3 locks held by kworker/1:3/5805:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900046c7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff88816f996230 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
2 locks held by syz-executor/9186:
1 lock held by syz.5.662/10396:
 #0: ffff888170fbc0d8 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.3.765/11556:
 #0: ffff888170fbc0d8 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz-executor/13133:
2 locks held by syz.6.986/13312:

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 8225 Comm: kworker/u10:7 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
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:x2apic_send_IPI+0x73/0xe0
Code: 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 42 41 8b 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f 5d e9 be 93 43 0a cc 89 fe 89 fd 48 c7
RSP: 0018:ffffc90004f6f6d0 EFLAGS: 00000206
RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830
RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000
RBP: ffffc90004f6f840 R08: ffffffff903339f7 R09: 1ffffffff206673e
R10: dffffc0000000000 R11: ffffffff81747300 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8881210201b0 R15: ffffffff8e294790
FS:  0000000000000000(0000) GS:ffff8882a9225000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f36bff000 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 smp_call_function_many_cond+0xc26/0x13d0
 on_each_cpu_cond_mask+0x3f/0x80
 smp_text_poke_batch_finish+0xec2/0x1160
 arch_jump_label_transform_apply+0x1c/0x30
 static_key_disable_cpuslocked+0xc5/0x1a0
 static_key_disable+0x1a/0x20
 toggle_allocation_gate+0x1fe/0x290
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
