INFO: task syz.3.13477:26797 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.13477     state:D stack:24608 pid:26797 tgid:26795 ppid:15461  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_version_get_doit+0x17c/0xc40
 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: 0033:0x7f5767b9cdd9
RSP: 002b:00007f5768aa7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5767e15fa0 RCX: 00007f5767b9cdd9
RDX: 0000000004000000 RSI: 0000200000000100 RDI: 0000000000000008
RBP: 00007f5767c32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5767e16038 R14: 00007f5767e15fa0 R15: 00007ffeca4292a8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff888176259948 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90000127c40 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbd0cc8 (rtnl_mutex){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work+0x29/0xa10
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/5637:
 #0: ffff8881765b50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900035732f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
5 locks held by kworker/u8:5/31982:
2 locks held by syz.2.11692/19718:
 #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
2 locks held by syz.3.13477/26797:
 #0: ffffffff8fc3ea70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xc40
2 locks held by syz.4.15315/1517:

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

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: 5247 Comm: klogd 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:kasan_unpoison+0x5d/0x70
Code: 03 48 ff c2 48 c1 ea 03 48 29 fa 4c 01 fa 31 f6 e8 c8 db 7f 09 4c 89 f0 48 83 e0 07 74 0b 4c 01 f3 48 c1 eb 03 42 88 04 3b 5b <41> 5e 41 5f e9 1a 9d 82 09 cc 90 0f 0b 90 eb ef 0f 1f 00 90 90 90
RSP: 0018:ffffc900033ff798 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8881a596bc00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffed1034b2d7c0
RBP: 0000000000482cc0 R08: ffffffff82246b4b R09: 0000000000000000
R10: ffffed1034b2d780 R11: fffffbfff2023b97 R12: ffff88810005d140
R13: 0000000000000200 R14: 0000000000000200 R15: dffffc0000000000
FS:  00007fdb1c65b380(0000) GS:ffff88818de54000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3cdb1ea2f8 CR3: 0000000175af2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __kasan_slab_alloc+0x58/0x80
 __kmalloc_node_track_caller_noprof+0x493/0x7b0
 __alloc_skb+0x2c1/0x7d0
 alloc_skb_with_frags+0xca/0x890
 sock_alloc_send_pskb+0x878/0x990
 unix_dgram_sendmsg+0x460/0x18e0
 __sys_sendto+0x672/0x710
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb1c7bd9b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffe9b548a18 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fdb1c7bd9b5
RDX: 000000000000004c RSI: 000055f2b821e330 RDI: 0000000000000003
RBP: 000055f2b8216910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007fdb1c94b212 R14: 00007ffe9b548b18 R15: 0000000000000000
 </TASK>
