INFO: task syz.3.6421:20971 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.6421      state:D stack:25952 pid:20971 tgid:20970 ppid:16076  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_rpc_status_get_dumpit+0xdc/0x1410
 genl_dumpit+0x10b/0x1b0
 netlink_dump+0x722/0xe80
 __netlink_dump_start+0x5cb/0x7e0
 genl_family_rcv_msg_dumpit+0x213/0x310
 genl_rcv_msg+0x5e8/0x7a0
 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: 0033:0x7f9ef8d9cdd9
RSP: 002b:00007f9ef9bcd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9ef9015fa0 RCX: 00007f9ef8d9cdd9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007f9ef8e32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9ef9016038 R14: 00007f9ef9015fa0 R15: 00007fff012881d8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by syslogd/5239:
 #0: ffff88812103ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150
 #1: ffff888121024588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
2 locks held by getty/5635:
 #0: ffff8881797200a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
3 locks held by kworker/1:7/6446:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc900040c7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
3 locks held by kworker/u10:7/13093:
 #0: ffff8881000ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90003857c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by syz.2.4068/15545:
 #0: ffffffff8fc3e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670
3 locks held by syz.3.6421/20971:
 #0: ffffffff8fc3e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffff8881792d26f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #2: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410
2 locks held by syz.0.7183/22752:
 #0: ffffffff8fc3e930 (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.1.7342/23112:
 #0: ffffffff8fc3e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8ea86b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xc40
3 locks held by kworker/0:2/23217:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc9000a9cfc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff88803063f240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
2 locks held by syz.5.7761/24096:
 #0: ffffffff8fc3e930 (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.4.7919/24443:
 #0: ffffffff8fc3e930 (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.8.9007/26958:
 #0: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0
 #1: ffffffff8e7648f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
2 locks held by syz.8.9007/26959:
 #0: ffffffff8f386f08 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xdf/0x1b10
 #1: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: ppp_ioctl+0x6ce/0x1b10
1 lock held by syz.8.9007/26960:
 #0: ffffffff8f386f08 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xdf/0x1b10
1 lock held by syz.6.9016/26980:
 #0: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10
1 lock held by syz.6.9016/26981:
 #0: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10
2 locks held by syz.7.9018/26985:
 #0: ffffffff9013b230 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8fbd0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0

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

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: 26958 Comm: syz.8.9007 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:lockdep_hardirqs_on_prepare+0x88/0x260
Code: 8b 05 4c 92 86 18 85 c0 75 0d 80 3d 46 01 70 0e 00 0f 85 62 01 00 00 85 c0 75 0f 65 8b 05 ec 6f 7b 11 85 c0 0f 85 a1 01 00 00 <65> 48 8b 1d a8 2d 7b 11 48 8b 83 48 0b 00 00 48 89 83 30 0b 00 00
RSP: 0018:ffffc900087367f8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000201 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8c27d560 RDI: ffffffff8c27d520
RBP: ffffc90008736990 R08: ffffffff9011dbb7 R09: 1ffffffff2023b76
R10: dffffc0000000000 R11: fffffbfff2023b77 R12: ffff8881066e3390
R13: ffff8881164e5c88 R14: ffffffff8a532d78 R15: dffffc0000000000
FS:  00007fbf8aa0c6c0(0000) GS:ffff88818de54000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558b6e0fb028 CR3: 0000000192eb2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 trace_hardirqs_on+0x28/0x40
 __local_bh_enable_ip+0xd0/0x130
 addrconf_ifdown+0x698/0x1a40
 addrconf_notify+0x1bc/0x1050
 notifier_call_chain+0x1be/0x400
 __dev_notify_flags+0x16d/0x310
 netif_change_flags+0xe8/0x1a0
 do_setlink+0xf82/0x4590
 rtnl_newlink+0x14ca/0x1bb0
 rtnetlink_rcv_msg+0x7d5/0xbe0
 netlink_rcv_skb+0x232/0x4b0
 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: 0033:0x7fbf89b9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbf8aa0c028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbf89e15fa0 RCX: 00007fbf89b9cdd9
RDX: 0000000000008024 RSI: 0000200000000140 RDI: 0000000000000007
RBP: 00007fbf89c32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbf89e16038 R14: 00007fbf89e15fa0 R15: 00007ffdc1dac0f8
 </TASK>
