INFO: task syz.3.1077:15996 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1077      state:D stack:27472 pid:15996 tgid:15995 ppid:15389  task_flags:0x400140 flags:0x00004004
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/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8591f8ebe9
RSP: 002b:00007f8592e59038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f85921b5fa0 RCX: 00007f8591f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f85921b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f85921b6038 R14: 00007f85921b5fa0 R15: 00007fff429f69a8
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
6 locks held by kworker/u8:0/12:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000f7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52b9f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x6a/0x4a0
 #4: ffff888100a90380 (&caifn->caifdevs.lock){+.+.}-{4:4}, at: caif_exit_net+0x7d/0x4a0
 #5: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by dhcpcd/5595:
 #0: ffff888108a5b6d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90
 #1: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200
2 locks held by getty/5675:
 #0: ffff8880270280a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/12386:
1 lock held by syz-executor/15001:
1 lock held by syz.3.1077/15996:
 #0: ffff888030ecc0e0 (&type->s_umount_key#58){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz-executor/16143:
3 locks held by syz-executor/17481:
7 locks held by syz-executor/17897:
 #0: ffff888110074428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
 #1: ffff888120c5c088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0
 #2: ffff88802301a2d8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0
 #3: ffffffff8edaf428 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360
 #4: ffff8881073db0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffff8881121da250 (&devlink->lock_key#17){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160
 #6: ffffffff8e13f840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570

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

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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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: 5595 Comm: dhcpcd 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_is_held_type+0x6c/0x190
Code: 8b 2c 25 08 50 a0 92 41 83 bd ec 0a 00 00 00 0f 85 d8 00 00 00 89 f5 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 24 4c 8b 24 24 <fa> 48 c7 c7 1c b3 9c 8d e8 17 17 00 00 65 ff 05 c0 e4 26 07 41 83
RSP: 0018:ffffc90002c4f628 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 30486be71f43a200
RDX: 0000000000000001 RSI: 00000000ffffffff RDI: ffff8881000e0188
RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff825e302c
R10: dffffc0000000000 R11: ffffed102001c025 R12: 0000000000000246
R13: ffff88801fd79cc0 R14: ffff8881000e0188 R15: dffffc0000000000
FS:  00007f29091ae740(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005578f3a5f000 CR3: 0000000022216000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 kernfs_parent+0x62/0x190
 kernfs_iop_get_link+0x118/0x6c0
 pick_link+0x636/0xe80
 step_into+0xc5d/0xf30
 link_path_walk+0x77b/0xea0
 path_openat+0x28c/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29092789a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffddf82d200 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000100a0 RCX: 00007f29092789a4
RDX: 0000000000000000 RSI: 00007ffddf83d498 RDI: 00000000ffffff9c
RBP: 00007ffddf83d498 R08: 0000000000000000 R09: 00007ffddf83d408
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffddf82d318 R14: 00007ffddf82d318 R15: 0000000000000000
 </TASK>
