INFO: task syz.9.1125:16313 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1125      state:D stack:25128 pid:16313 tgid:16312 ppid:16084  task_flags:0x400040 flags:0x00080002
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/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f77c458eec9
RSP: 002b:00007f77c54c0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f77c47e5fa0 RCX: 00007f77c458eec9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000600
RBP: 00007f77c4611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000580 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f77c47e6038 R14: 00007f77c47e5fa0 R15: 00007ffecccd2288
 </TASK>
INFO: task syz.9.1125:16334 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1125      state:D stack:28904 pid:16334 tgid:16312 ppid:16084  task_flags:0x400040 flags:0x00080002
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
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f77c458eec9
RSP: 002b:00007f77c549f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f77c47e6090 RCX: 00007f77c458eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f77c47e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f77c47e6128 R14: 00007f77c47e6090 R15: 00007ffecccd2288
 </TASK>
INFO: task syz.9.1125:16336 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1125      state:D stack:28904 pid:16336 tgid:16312 ppid:16084  task_flags:0x400040 flags:0x00080002
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
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f77c458eec9
RSP: 002b:00007f77c547e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f77c47e6180 RCX: 00007f77c458eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f77c47e6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f77c47e6218 R14: 00007f77c47e6180 R15: 00007ffecccd2288
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/1:0/24:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900001e7ba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8881a4ff6240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
7 locks held by kworker/u9:1/28:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5557:
2 locks held by getty/5637:
 #0: ffff8881711e10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by syz-executor/12634:
1 lock held by syz.9.1125/16313:
 #0: ffff88810239c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1125/16334:
 #0: ffff88810239c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1125/16336:
 #0: ffff88810239c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1196/17060:
 #0: ffff88810239c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1320/18250:
 #0: ffff88810239c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1453/19778:
 #0: ffff88810239c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/19787:
 #0: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 12634 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_lock+0x12e/0x290
Code: 00 48 89 df be 04 00 00 00 e8 ee ad 87 00 48 8d 7c 24 40 be 04 00 00 00 e8 df ad 87 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 dd 00 00 00 65 8b 1d d9 88 f3 10 48 b9 00 00 00 00 00 fc ff
RSP: 0018:ffffc900078df560 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88811f4d2d58 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900078df5a0
RBP: ffffc900078df620 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000f1beb4 R12: ffff88811f4d2d68
R13: ffff88811f4d2d60 R14: 1ffff11023e9a5ad R15: 1ffff11023e9a5ac
FS:  000055557d99d500(0000) GS:ffff88818e70f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1289ff000 CR3: 000000016c430000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 writeback_single_inode+0x34/0x6a0
 sync_inode_metadata+0xb9/0x110
 f2fs_write_checkpoint+0xaf2/0x2440
 kill_f2fs_super+0x2cc/0x6d0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xe9/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0afbd901f7
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:00007ffc40907ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f0afbe11d7d RCX: 00007f0afbd901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc40907f60
RBP: 00007ffc40907f60 R08: 000000000000f0fc R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc40908ff0
R13: 00007f0afbe11d7d R14: 000000000004c946 R15: 00007ffc40909030
 </TASK>
