INFO: task syz.1.2086:13477 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2086      state:D stack:26168 pid:13477 tgid:13476 ppid:11693  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_threads_set_doit+0x2cb/0x960
 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: 0033:0x7efccfd8eba9
RSP: 002b:00007efcd0bbc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efccffd5fa0 RCX: 00007efccfd8eba9
RDX: 0000000004000000 RSI: 0000200000000780 RDI: 0000000000000007
RBP: 00007efccfe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efccffd6038 R14: 00007efccffd5fa0 R15: 00007fff81e85098
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u9:1/29:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000062fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53ab48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5595:
 #0: ffffffff8f53ab48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5677:
 #0: ffff8880233d10a0 (&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
5 locks held by kworker/u8:4/7236:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006cf7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52dc90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f53ab48 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890
 #4: ffffffff8e13fbb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by syz.0.1654/12001:
 #0: ffffffff8f5a0270 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e419548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2cb/0x960
2 locks held by syz.1.2086/13477:
 #0: ffffffff8f5a0270 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e419548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2cb/0x960
2 locks held by syz.2.2353/14455:
 #0: ffffffff8f5a0270 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e419548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0
2 locks held by syz.3.3042/16925:
 #0: ffffffff8f5a0270 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e419548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2cb/0x960
2 locks held by syz-executor/17456:
 #0: ffffffff8fa5c970 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f53ab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
2 locks held by syz-executor/17480:
 #0: ffffffff8f52dc90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f53ab48 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800
1 lock held by syz.5.3165/17491:
 #0: ffffffff8f53ab48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
3 locks held by syz.5.3168/17501:

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

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+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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17501 Comm: syz.5.3168 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:netdev_core_pick_tx+0x43/0x350
Code: 49 bd 00 00 00 00 00 fc ff df e8 f8 5d 5c f8 4d 8d be a0 00 00 00 4d 89 fc 49 c1 ec 03 43 0f b6 04 2c 84 c0 0f 85 2d 02 00 00 <41> 8b 2f 83 c5 f7 bf f8 ff ff ff 89 ee e8 0b 62 5c f8 83 fd f8 73
RSP: 0018:ffffc90000007420 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880393dc000 RCX: ffff888028e65640
RDX: 0000000000000100 RSI: ffff888048b06900 RDI: ffff8880393dc000
RBP: ffffc90000007770 R08: ffffffff8fa3b237 R09: 1ffffffff1f47646
R10: dffffc0000000000 R11: fffffbfff1f47647 R12: 1ffff11009160d34
R13: dffffc0000000000 R14: ffff888048b06900 R15: ffff888048b069a0
FS:  00007f0b92ac16c0(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fac9613131 CR3: 0000000111028000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __dev_queue_xmit+0x804/0x3b50
 ip6_finish_output2+0x11bc/0x16a0
 ndisc_send_skb+0xb54/0x1440
 addrconf_rs_timer+0x369/0x670
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__sanitizer_cov_trace_pc+0x5d/0x70
Code: 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <c3> cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc90004fb7350 EFLAGS: 00000287
RAX: ffffffff820ec0e9 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9002c608000 RSI: 000000000007e8d7 RDI: 000000000007e8d8
RBP: 0000000000000001 R08: ffffea0004b4c233 R09: 1ffffd4000969846
R10: dffffc0000000000 R11: fffff94000969847 R12: dffffc0000000000
R13: 00007f0b90b25000 R14: ffffea0004b4c200 R15: ffffc90004fb7840
 __tlb_remove_folio_pages+0x19/0x30
 unmap_page_range+0x20ac/0x4370
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x430
 copy_mm+0x1f3/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0b91b8eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0b92ac0fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f0b91dd5fa0 RCX: 00007f0b91b8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0b91c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b91dd6038 R14: 00007f0b91dd5fa0 R15: 00007ffeaf5c6038
 </TASK>
