INFO: task syz.1.11563:32056 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.11563     state:D stack:27144 pid:32056 tgid:32055 ppid:5854   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 nfsd_nl_listener_get_doit+0x10a/0x5e0
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 ____sys_sendmsg+0x972/0x9f0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f22e319c799
RSP: 002b:00007f22e4019028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f22e3415fa0 RCX: 00007f22e319c799
RDX: 0000000004000000 RSI: 0000200000000940 RDI: 0000000000000003
RBP: 00007f22e3232c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f22e3416038 R14: 00007f22e3415fa0 R15: 00007ffd64708198
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff8881012ae148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90000117c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbbf430 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: 
ffffffff8fbcdbc8 (rtnl_mutex){+.+.}-{4:4}, at: ipmr_net_exit_batch+0x20/0x90
7 locks held by kworker/u9:1/32:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5630:
 #0: ffff8881135100a0 (&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.0.11207/31218:
 #0: ffffffff8fc3b930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea85f88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
2 locks held by syz.1.11563/32056:
 #0: ffffffff8fc3b930
 (
cb_lock
){++++}-{4:4}
, at: genl_rcv+0x19/0x40
 #1: 
ffffffff8ea85f88
 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0
2 locks held by syz.4.14320/6174:
 #0: ffffffff9a7ab538 (nfnl_subsys_ipset){+.+.}-{4:4}, at: call_ad+0x292/0xb60
 #1: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.4.14320/6179:
 #0: ffffffff9a7ab538 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0
2 locks held by syz.2.14324/6176:
 #0: ffffffff8fbcdbc8 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0x87/0x1f0
 #1: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770

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

NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: kworker/u9:0 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
Workqueue: xprtiod xs_tcp_setup_socket
RIP: 0010:io_serial_out+0x7c/0xc0
Code: f5 84 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6c 37 ef fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 ac 70 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000a174f0 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888109610237 R09: 1ffff110212c2046
R10: dffffc0000000000 R11: ffffffff8540ab50 R12: dffffc0000000000
R13: ffffffff9a2b9a4f R14: ffffffff9a5d1980 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88818de5d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fada43e9e80 CR3: 00000001c59e0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x140c/0x1ba0
 console_flush_all+0x718/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 xs_tcp_setup_socket+0xa63/0xc10
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
