INFO: task syz.5.486:7765 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.486       state:D stack:28904 pid:7765  tgid:7764  ppid:6558   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: 0033:0x7fd0c1f8efc9
RSP: 002b:00007fd0c2d6a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd0c21e5fa0 RCX: 00007fd0c1f8efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd0c21e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd0c21e6038 R14: 00007fd0c21e5fa0 R15: 00007fffe5a7cd18
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/1:0/24:
 #0: ffff888166fb3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900001e7ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88816c680198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff8881726f5198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88816b70e160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #5: ffffffff8dde2830 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0
1 lock held by khungtaskd/34:
 #0: ffffffff8df3d620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:5/1092:
 #0: ffff888100089948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90007c9fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2cb648 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by getty/5641:
 #0: ffff8881743ab0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/5813:
4 locks held by udevd/7086:
 #0: ffff88812029e668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20
 #1: ffff8881067de088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420
 #2: ffff8881a8f51a58 (kn->active#30){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420
 #3: ffff8881726f5198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0
1 lock held by syz.5.486/7765:
 #0: ffff8881ba0c60e0 (&type->s_umount_key#58){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by udevd/8411:
2 locks held by syz.0.1110/10188:
2 locks held by syz.1.1120/10215:
 #0: ffffffff8f2cb648 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x346/0x700
 #1: ffffffff8df430b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz.1.1120/10225:
 #0: ffffffff8f2cb648 (rtnl_mutex){+.+.}-{4:4}, at: bpf_xdp_link_update+0x2f/0x670

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

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+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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5813 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:check_preemption_disabled+0x3/0x120
Code: bf 8b 48 c7 c6 40 07 bf 8b eb 1c 66 66 66 2e 0f 1f 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 53 48 83 ec 10 65 48 8b 05 de d4 27 07 48 89 44 24 08 65 8b
RSP: 0018:ffffc90003ea77f8 EFLAGS: 00000092
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 950a3f794da97f00
RDX: 0000000000000000 RSI: ffffffff8d8f3eb0 RDI: ffffffff8bbf0760
RBP: ffffffff840fda8a R08: 0000000000000000 R09: ffffffff840fda8a
R10: dffffc0000000000 R11: ffffed103566721c R12: 0000000000000000
R13: ffff8881ab338c08 R14: 0000000000000001 R15: 0000000000000246
FS:  0000555587e80500(0000) GS:ffff8882a9f3d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f57ee5ff800 CR3: 00000001ba8e8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x130/0x360
 _raw_spin_lock+0x2e/0x40
 f2fs_write_checkpoint+0xa9a/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: 0033:0x7fe5651902f7
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:00007ffffa46a898 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe565211d7d RCX: 00007fe5651902f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffffa46a950
RBP: 00007ffffa46a950 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffffa46b9e0
R13: 00007fe565211d7d R14: 00000000000122b4 R15: 00007ffffa46ba20
 </TASK>
