INFO: task syz-executor:12595 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:24160 pid:12595 tgid:12595 ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 ip_tunnel_init_net+0x2ab/0x800
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f96b7d903e7
RSP: 002b:00007ffe5a6a6788 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f96b7fc5f40 RCX: 00007f96b7d903e7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f96b7fc67b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:3/69:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000175fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by getty/5672:
 #0: ffff888109ff60a0 (&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 kworker/u8:2/5860:
3 locks held by kworker/u8:3/5876:
 #0: ffff888021731148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000347fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
5 locks held by kworker/u8:4/5890:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000355fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52b9f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990
 #4: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by syz-executor/12585:
 #0: ffffffff8f52b9f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0
2 locks held by syz-executor/12591:
 #0: ffffffff8f52b9f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0
2 locks held by syz-executor/12595:
 #0: ffffffff8f52b9f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800
1 lock held by syz-executor/12657:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/12664:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/12668:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/12681:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/12689:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/12694:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

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

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+0x3fc/0x770
 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: 5860 Comm: kworker/u8:2 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: bat_events batadv_tt_purge
RIP: 0010:rcu_lockdep_current_cpu_online+0x6a/0x120
Code: 00 00 49 be 00 00 00 00 00 fc ff df 48 8d 1c dd 10 fd bd 8d 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 96 73 7c 00 <48> 8b 03 48 8d 98 80 ff a1 92 48 8d b8 a8 ff a1 92 48 89 f8 48 c1
RSP: 0018:ffffc90000006708 EFLAGS: 00000246
RAX: 1ffffffff1b7bfa2 RBX: ffffffff8dbdfd10 RCX: feaabe8823977800
RDX: ffff888020f85640 RSI: ffffffff8be33660 RDI: ffffffff8be33620
RBP: 0000000000000001 R08: ffffc9000000680f R09: 0000000000000000
R10: ffffc90000006800 R11: fffff52000000d02 R12: dffffc0000000000
R13: ffffc900000067e0 R14: dffffc0000000000 R15: ffff8880227ce300
FS:  0000000000000000(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9c5686a4a0 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 rcu_read_lock_held+0x1e/0x50
 fib6_node_lookup_1+0x10c/0x8a0
 fib6_node_lookup+0xcc/0x1b0
 fib6_table_lookup+0xbf/0xa80
 ip6_pol_route+0x222/0x1180
 fib6_rule_lookup+0x52f/0x6f0
 ip6_route_input+0x6ce/0xa50
 ip6_rcv_finish+0x141/0x2e0
 ip_sabotage_in+0x1e1/0x270
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x206/0x3a0
 __netif_receive_skb+0xd3/0x380
 netif_receive_skb+0x1cb/0x790
 NF_HOOK+0xa0/0x390
 br_handle_frame_finish+0x14d1/0x19b0
 br_nf_hook_thresh+0x3c6/0x4a0
 br_nf_pre_routing_finish_ipv6+0x948/0xd00
 br_nf_pre_routing_ipv6+0x37e/0x6b0
 br_handle_frame+0x982/0x14c0
 __netif_receive_skb_core+0x10b9/0x4020
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 batadv_tt_local_purge+0x2a7/0x340
 batadv_tt_purge+0x35/0x9e0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
