INFO: task syz.9.1397:19728 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1397      state:D stack:26720 pid:19728 tgid:19691 ppid:18901  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
 lookup_slow+0x46/0x70
 path_lookupat+0x3f5/0x8c0
 filename_lookup+0x256/0x5d0
 filename_linkat+0x11a/0x600
 __se_sys_link+0x55/0x2c0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0ca79c799
RSP: 002b:00007fb0cb6d4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007fb0caa16090 RCX: 00007fb0ca79c799
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000200000000140
RBP: 00007fb0ca832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb0caa16128 R14: 00007fb0caa16090 R15: 00007fff29558ff8
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:1/13:
 #0: ffff8881012ae148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbbf970 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u10:3/2254:
 #0: ffff888162691148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc9000b8bfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff888173c1a0e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff88811c35e680 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530
2 locks held by dhcpcd/5553:
 #0: ffff888104b8d6f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #1: ffffffff8fbce108 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200
2 locks held by getty/5635:
 #0: ffff88810d3900a0 (&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
4 locks held by syz-executor/16029:
3 locks held by syz-executor/16077:
4 locks held by syz-executor/16959:
4 locks held by syz.9.1397/19692:
1 lock held by syz.9.1397/19728:
 #0: ffff88811c35ea30 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: lookup_slow+0x46/0x70
1 lock held by syz.1.1432/20069:
 #0: ffff88811f2720e0 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x289/0x3d0
3 locks held by syz.7.1476/20456:
 #0: ffff88819af3a4f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff88810c076420 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev+0x2aa/0x990
 #2: ffff8881b5cd80e0 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.6.1534/20786:
 #0: ffff8881181220e0 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
4 locks held by kworker/u10:0/21078:
 #0: ffff8881000ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90003bd7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbce108 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
 #3: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
1 lock held by syz.5.1597/21231:
 #0: ffff8881b5cd80e0 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
3 locks held by kworker/u8:5/21690:
 #0: ffff888170e1d948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90007e6fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbce108 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0
1 lock held by syz-executor/22024:
 #0: ffffffff8fbce108 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0

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

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: 16077 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:igrab+0x9b/0x1e0
Code: 2a 7b ff 85 ed 0f 84 d2 00 00 00 e8 9f 26 7b ff eb 05 e8 98 26 7b ff 4c 8d bb d0 00 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 ea 00 00 00 41 8b 2f 89 ee 81 e6 80 01 00 00 31 ff e8
RSP: 0018:ffffc90004d37810 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff888011d552f8 RCX: ffff8881130c8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520009a6ef0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888011d55378 R15: ffff888011d553c8
FS:  000055557caeb500(0000) GS:ffff8882a945d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff4995e92f8 CR3: 000000011dc50000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 f2fs_write_checkpoint+0xb73/0x26a0
 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: 0033:0x7ff86e39d9d7
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:00007ffe39e70e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff86e432050 RCX: 00007ff86e39d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe39e70f10
RBP: 00007ffe39e70f10 R08: 00007ffe39e71f10 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe39e71fa0
R13: 00007ff86e432050 R14: 0000000000060196 R15: 00007ffe39e71fe0
 </TASK>
