INFO: task syz.0.11209:10820 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.11209     state:D stack:24824 pid:10820 tgid:10819 ppid:5613   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 nfsd_nl_threads_get_doit+0x1c0/0x790
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x813/0xb40
 ____sys_sendmsg+0x972/0x9f0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3ddf79cdd9
RSP: 002b:00007f3de065d028 EFLAGS: 00000246
 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3ddfa15fa0 RCX: 00007f3ddf79cdd9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f3ddf832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ddfa16038 R14: 00007f3ddfa15fa0 R15: 00007ffe550f4cc8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
5 locks held by kworker/u9:6/1110:
2 locks held by getty/5435:
 #0: ffff88816b3560a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: 
ffffc900034732e8
 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
2 locks held by syz.1.11121/10495:
 #0: 
ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: 
ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
2 locks held by syz.0.11209/10820:
 #0: 
ffffffff8fe3f0e8
 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: 
ffffffff8ec8aca0
 (
nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790
2 locks held by syz.3.11653/12444:
 #0: 
ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: 
ffffffff8ec8aca0 (
nfsd_mutex
){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670

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

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+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 1110 Comm: kworker/u9:6 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:detach_timer+0x124/0x2d0
Code: 3c 28 00 74 08 4c 89 e7 e8 e9 d4 7e 00 4d 89 3c 24 4d 85 ff 74 46 e8 7b 98 13 00 49 83 c7 08 4c 89 f8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ff e8 c2 d4 7e 00 4d 89 27 80 7c 24 04 00 74 2a e8 53
RSP: 0018:ffffc90000007d38 EFLAGS: 00000046
RAX: 1ffff11023cace03 RBX: 1ffff1102215a882 RCX: ffff888109db1d80
RDX: 0000000000000100 RSI: ffffffff8c28adc0 RDI: ffffffff8c28ad80
RBP: dffffc0000000000 R08: ffffffff9030aff7 R09: 1ffffffff20615fe
R10: dffffc0000000000 R11: fffffbfff20615ff R12: ffffc90000007e40
R13: ffff888110ad4418 R14: 1ffff1102215a883 R15: ffff88811e567018
FS:  0000000000000000(0000) GS:ffff88818dc8f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffe0e6bfc0 CR3: 000000019878c000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __run_timer_base+0x5d3/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:vprintk_emit+0x45d/0x560
Code: 0f 84 44 ff ff ff e8 a2 29 21 00 fb eb 44 e8 9a 29 21 00 e8 45 0f 04 0a 4d 85 f6 74 94 e8 8b 29 21 00 fb 48 c7 c7 a0 f1 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18
RSP: 0018:ffffc90007327880 EFLAGS: 00000293
RAX: ffffffff81a495e5 RBX: ffffffff81a4945f RCX: ffff888109db1d80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e94f1a0
RBP: ffffc90007327930 R08: ffffffff9030aff7 R09: 1ffffffff20615fe
R10: dffffc0000000000 R11: fffffbfff20615ff R12: 0000000000000000
R13: 0000000000000039 R14: 0000000000000200 R15: 1ffff92000e64f14
 _printk+0xdd/0x130
 xs_tcp_setup_socket+0xa63/0xc10
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
