INFO: task syz.6.21359:26518 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.21359     state:D stack:24768 pid:26518 tgid:26517 ppid:23143  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 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+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: 0033:0x7f972979cdd9
RSP: 002b:00007f972a5b6028 EFLAGS: 00000246
 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9729a15fa0 RCX: 00007f972979cdd9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000008
RBP: 00007f9729832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9729a16038 R14: 00007f9729a15fa0 R15: 00007ffd117fb9b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5635:
 #0: ffff88816a00c0a0 (&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
3 locks held by kworker/u8:4/14359:
 #0: 
ffff888173204948
 (
(wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: 
ffffc9002591fc40
 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbd0cc8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0
2 locks held by syz.1.20501/22766:
 #0: ffffffff8fc3ea70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
7 locks held by kworker/u10:1/25659:
2 locks held by syz.6.21359/26518:
 #0: ffffffff8fc3ea70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790
3 locks held by kworker/u9:2/31310:
 #0: ffff8881000ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc900307d7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbd0cc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
3 locks held by syz.7.22726/32319:
 #0: ffff88803552a090 (&uprobe->register_rwsem){+.+.}-{4:4}, at: uprobe_unregister_nosync+0x31/0x1d0
 #1: ffffffff8e82ac50 (dup_mmap_sem){++++}-{0:0}, at: register_for_each_vma+0x32/0xc30
 #2: ffffffff8e7648f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.7.22726/32321:
 #0: ffffffff8fbd0cc8 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150
2 locks held by syz.4.22728/32336:
 #0: ffffffff901224f0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8e7647c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580
3 locks held by syz.4.22728/32338:
 #0: ffffffff901224f0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: 
ffffffff8fbd0cc8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_newlink+0x883/0x1bb0
 #2: 
ffffffff8e7648f8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: synchronize_rcu_expedited+0x2d0/0x770

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

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: 25659 Comm: kworker/u10:1 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:its_return_thunk+0x0/0x10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 2b 9a 80 f5 cc
RSP: 0018:ffffc90000a08b80 EFLAGS: 00000246
RAX: ffffffff89b69fec RBX: 0000000000000000 RCX: ffff88818c760000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881ce8a8f88 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141174 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff8881ce8a8fa0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a9454000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd223b2b440 CR3: 000000002b568000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 pie_calculate_probability+0x42c/0x7e0
 fq_pie_timer+0x288/0x5b0
 call_timer_fn+0x192/0x640
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x870
 __irq_exit_rcu+0x5f/0x150
 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 92 43 21 00 fb eb 44 e8 8a 43 21 00 e8 55 52 0b 0a 4d 85 f6 74 94 e8 7b 43 21 00 fb 48 c7 c7 00 0a 75 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 6b 16
RSP: 0018:ffffc90025d5f880 EFLAGS: 00000293
RAX: ffffffff81a49045 RBX: ffffffff81a48ebf RCX: ffff88818c760000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e750a00
RBP: ffffc90025d5f930 R08: ffffffff9011dcb7 R09: 1ffffffff2023b96
R10: dffffc0000000000 R11: fffffbfff2023b97 R12: 0000000000000000
R13: 0000000000000039 R14: 0000000000000200 R15: 1ffff92004babf14
 _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>
