INFO: task syz.8.481:9938 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.481       state:D stack:25560 pid:9938  tgid:9936  ppid:9020   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 ksys_sync+0xa0/0x170
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8e6819acb9
RSP: 002b:00007f8e663d5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f8e68416090 RCX: 00007f8e6819acb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8e68416090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8e68416128 R14: 00007f8e68416090 R15: 00007ffecf13c758
 </TASK>
INFO: task syz.2.489:9977 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.489       state:D stack:24856 pid:9977  tgid:9976  ppid:8920   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x516/0x990
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa26859acb9
RSP: 002b:00007fa26943b028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa268815fa0 RCX: 00007fa26859acb9
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000801
RBP: 00007fa268608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa268816038 R14: 00007fa268815fa0 R15: 00007fffd1eb81e8
 </TASK>
INFO: task syz.2.489:9995 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.489       state:D stack:28728 pid:9995  tgid:9976  ppid:8920   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x516/0x990
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa26859acb9
RSP: 002b:00007fa26941a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa268816090 RCX: 00007fa26859acb9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: ffffffff80000901
RBP: 00007fa268608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa268816128 R14: 00007fa268816090 R15: 00007fffd1eb81e8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:15/4570:
 #0: ffff888100089948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90025027bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8f7a8848 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by dhcpcd/5577:
 #0: ffff8881135aa6f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #1: ffffffff8f7a8848 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200
2 locks held by getty/5659:
 #0: ffff88810a3320a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz-executor/5838:
5 locks held by kworker/u8:3/5863:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90004e87bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8f799ed0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0
 #3: ffffffff8f7a8848 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0xa10
 #4: ffffffff8e360c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.8.481/9938:
 #0: ffff88811362c0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.2.489/9977:
 #0: ffff88811362c0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.2.489/9995:
 #0: ffff88811362c0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.5.617/11571:
 #0: ffff88811362c0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.5.617/11582:
 #0: ffff88811362c0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.2.794/12881:
 #0: ffff88811362c0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz-executor/12945:
 #0: ffff8881714d80e0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffffffff8e360c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
2 locks held by syz-executor/13322:
 #0: ffffffff8ef0f628 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f7a8848 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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+0xf90/0xfe0
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 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: 5838 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:lock_release+0x266/0x3a0
Code: 89 f6 48 8b 54 24 18 e8 e8 2e 00 00 48 8b 5c 24 08 48 c7 c7 5b 8c d3 8d e8 27 46 d9 09 b8 ff ff ff ff 65 0f c1 05 7a 61 30 11 <83> f8 01 75 2e 9c 58 a9 00 02 00 00 75 42 f7 c3 00 02 00 00 75 47
RSP: 0018:ffffc90004d27828 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000206 RCX: 0000000080000001
RDX: 0000000000000002 RSI: ffffffff8dd38c5b RDI: ffffffff8be73880
RBP: ffff888110366340 R08: ffff888167921b83 R09: 1ffff1102cf24370
R10: dffffc0000000000 R11: ffffed102cf24371 R12: 0000000000000002
R13: 0000000000000002 R14: ffff888111a00ca0 R15: ffff8881103657c0
FS:  000055556a125500(0000) GS:ffff88818e328000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5271d6a620 CR3: 000000011abd0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_unlock+0x16/0x50
 f2fs_write_checkpoint+0xb67/0x2490
 kill_f2fs_super+0x308/0x710
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x437/0x4d0
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xed/0x480
 do_syscall_64+0x2b7/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f77c299bf17
Code: a2 c7 05 7c 96 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffefdd47ae8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f77c2a0471f RCX: 00007f77c299bf17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffefdd47ba0
RBP: 00007ffefdd47ba0 R08: 0000000000000000 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffefdd48c30
R13: 00007f77c2a0471f R14: 000000000001ceb0 R15: 00007ffefdd48c70
 </TASK>
