INFO: task syz.4.863:13599 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.863       state:D stack:24608 pid:13599 tgid:13598 ppid:12884  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 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+0x540/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa35b79c799
RSP: 002b:00007fa35c717028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa35ba15fa0 RCX: 00007fa35b79c799
RDX: 0000000000000000 RSI: 0000200000000340 RDI: ffffffff80000800
RBP: 00007fa35b832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa35ba16038 R14: 00007fa35ba15fa0 R15: 00007fffd70a4958
 </TASK>
INFO: task syz.4.863:13622 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.863       state:D stack:26456 pid:13622 tgid:13598 ppid:12884  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 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+0x540/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa35b79c799
RSP: 002b:00007fa35c6f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa35ba16090 RCX: 00007fa35b79c799
RDX: 0000000000000000 RSI: 0000200000000340 RDI: ffffffff80000800
RBP: 00007fa35b832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa35ba16128 R14: 00007fa35ba16090 R15: 00007fffd70a4958
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5554:
 #0: ffffffff8fbcea88 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30
2 locks held by getty/5636:
 #0: ffff88816ad7c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
3 locks held by kworker/u8:4/5964:
 #0: ffff88810bae3148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc900071cfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbcea88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0
2 locks held by syz-executor/8519:
1 lock held by syz.4.863/13599:
 #0: ffff8881108ea0e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.863/13622:
 #0: ffff8881108ea0e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.998/15367:
 #0: ffff8881108ea0e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x289/0x3d0
3 locks held by syz-executor/17050:
 #0: ffffffff8fbcea88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0
 #1: ffff8881a91ecd88 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: do_setlink+0x3d2/0x4590
 #2: ffffffff8e764878 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770

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

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+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 8519 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:reacquire_held_locks+0x14/0x190
Code: 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 54 53 48 89 cb 89 d5 83 3d 1c a6 85 18 00 <75> 0d 9c 58 a9 00 02 00 00 0f 85 06 01 00 00 4c 63 f5 41 83 fe 31
RSP: 0018:ffffc900055bf4f0 EFLAGS: 00000046
RAX: 7dd6af930c80e051 RBX: ffffc900055bf544 RCX: ffffc900055bf544
RDX: 0000000000000003 RSI: 0000000000000004 RDI: ffff888173b71d40
RBP: 0000000000000003 R08: ffff8881697aa077 R09: 1ffff1102d2f540e
R10: dffffc0000000000 R11: ffffed102d2f540f R12: 0000000000000003
R13: 0000000000000003 R14: ffff8881697aa0d8 R15: ffff888173b71d40
FS:  0000555589152500(0000) GS:ffff8882a945d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f589d7c60e0 CR3: 0000000172e60000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_release+0x199/0x3d0
 _raw_spin_unlock+0x16/0x50
 writeback_single_inode+0x857/0xdc0
 sync_inode_metadata+0x122/0x1d0
 f2fs_write_checkpoint+0xb93/0x26a0
 kill_f2fs_super+0x314/0x720
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x437/0x4d0
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xed/0x480
 do_syscall_64+0x32d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e3c59d9d7
Code: a2 c7 05 1c fd 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:00007fff296149b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5e3c632050 RCX: 00007f5e3c59d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff29614a70
RBP: 00007fff29614a70 R08: 00007fff29615a70 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff29615b00
R13: 00007f5e3c632050 R14: 000000000003bf2e R15: 00007fff29615b40
 </TASK>
