INFO: task syz.6.12379:30514 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.12379     state:D stack:26880 pid:30514 tgid:30512 ppid:19591  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 nfsd_nl_listener_set_doit+0x137/0x1690
 genl_family_rcv_msg_doit+0x215/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe3418ec29
RSP: 002b:00007efe34fe5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efe343d6090 RCX: 00007efe3418ec29
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000007
RBP: 00007efe34211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe343d6128 R14: 00007efe343d6090 R15: 00007fff53b34148
 </TASK>

Showing all locks held in the system:
3 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: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5673:
 #0: ffff8881071df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz.3.11604/26904:
 #0: ffffffff8f59fb50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.6.12379/30514:
 #0: ffffffff8f59fb50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.8.12887/436:
 #0: ffffffff8f59fb50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.9.13645/4251:
 #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.9.13645/4267:
 #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70
1 lock held by syz.9.13645/4270:
 #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150
2 locks held by syz.7.13646/4256:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0
2 locks held by syz.5.13648/4265:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0

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

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+0x439/0x7d0
 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: 4264 Comm: syz.5.13648 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:__free_object+0x186/0x6d0
Code: 08 4c 89 f7 e8 1b 4b 52 fd 4d 8b 26 49 83 c4 18 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 fe 4a 52 fd 49 8b 1c 24 <4d> 8d 67 18 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8
RSP: 0018:ffffc900006afb80 EFLAGS: 00000046
RAX: 1ffff11008173961 RBX: ffff888122bcb380 RCX: 7a1eb43e6a2ddf00
RDX: 0000000000000000 RSI: ffffffff8be33ee0 RDI: ffffffff8be33ea0
RBP: ffffc900006afc70 R08: ffffffff8fa38f37 R09: 1ffffffff1f471e6
R10: dffffc0000000000 R11: fffffbfff1f471e7 R12: ffff888040b9cb08
R13: dffffc0000000000 R14: ffff88813663b9c0 R15: ffff88803c750b60
FS:  000055555d8fd500(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f096e5b0d58 CR3: 000000003bcb8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 debug_object_free+0x2a2/0x340
 hrtimer_nanosleep+0x2a6/0x360
 __se_sys_clock_nanosleep+0x2f1/0x380
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f433cdc14e5
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007ffd1bdcc100 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007f433cfd5fa0 RCX: 00007f433cdc14e5
RDX: 00007ffd1bdcc140 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f433cfd7da0 R08: 0000000000000000 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000001a2f99
R13: 00007f433cfd6090 R14: ffffffffffffffff R15: 00007ffd1bdcc280
 </TASK>
