INFO: task syz.0.2438:11634 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2438      state:D stack:26304 pid:11634 tgid:11632 ppid:5868   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1550/0x5060
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x829/0x1340
 nfnetlink_rcv_msg+0xa6e/0x12c0
 netlink_rcv_skb+0x232/0x4b0
 nfnetlink_rcv+0x2c0/0x27b0
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x4d7/0x810
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0xf0/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b6999acb9
RSP: 002b:00007f3b6a782028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3b69c06090 RCX: 00007f3b6999acb9
RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000000000000004
RBP: 00007f3b69a08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b69c06128 R14: 00007f3b69c06090 R15: 00007ffc6a53d888
 </TASK>

Showing all locks held in the system:
7 locks held by kworker/u8:0/12:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90000117b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8f708170 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0
 #3: ffff88810c1520e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0
 #4: ffff88810c153250 (&devlink->lock_key){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0
 #5: ffffffff8f715208 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680
 #6: ffffffff8e347638 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3f2/0x7e0
1 lock held by khungtaskd/35:
 #0: ffffffff8e341ae0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:13/4720:
2 locks held by getty/5662:
 #0: ffff88811303d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
6 locks held by kworker/u8:2/5664:
3 locks held by kworker/0:9/7784:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90004e97b80 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8e347500 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580
5 locks held by syz.2.2437/11623:
1 lock held by syz.0.2438/11634:
 #0: ffffffff9a1e3338 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0
2 locks held by syz-executor/11639:
 #0: ffffffff8f708170 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cb/0x570
 #1: ffffffff8f715208 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840
2 locks held by syz-executor/11642:
 #0: ffffffff8f708170 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cb/0x570
 #1: ffffffff8f479cd0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x92/0x350
2 locks held by syz-executor/11646:
 #0: ffffffff8f708170 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cb/0x570
 #1: ffffffff8f715208 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840
6 locks held by syz-executor/11651:
2 locks held by syz-executor/11655:
 #0: ffffffff8f708170 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cb/0x570
 #1: ffffffff8f715208 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x6a/0x4a0
2 locks held by kworker/u8:6/11659:
1 lock held by syz-executor/11666:
 #0: ffffffff8f715208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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+0x1a9/0x280
 nmi_cpu_backtrace+0x3a9/0x3e0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf90/0xfe0
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 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: 11659 Comm: kworker/u8:6 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:__asan_memcpy+0x40/0x70
Code: 64 24 20 48 89 f7 48 89 d6 31 d2 4c 89 e1 e8 37 e4 ff ff 84 c0 74 2c 4c 89 ff 48 89 de ba 01 00 00 00 4c 89 e1 e8 20 e4 ff ff <84> c0 74 15 4c 89 ff 4c 89 f6 48 89 da 5b 41 5c 41 5e 41 5f e9 67
RSP: 0018:ffffc90000006c78 EFLAGS: 00000256
RAX: ffffc90000006d01 RBX: 0000000000000010 RCX: ffffffff8a242d8c
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90000006d38
RBP: ffffc90000006e48 R08: ffffc90000006d47 R09: 1ffff92000000da8
R10: dffffc0000000000 R11: fffff52000000da9 R12: ffffffff8a242d8c
R13: dffffc0000000000 R14: ffff88810975aa18 R15: ffffc90000006d38
FS:  0000000000000000(0000) GS:ffff88818e41f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f483591e866 CR3: 0000000116a94000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 ip6_route_input+0x23c/0xad0
 ip6_rcv_finish+0x141/0x2e0
 ip_sabotage_in+0x1e1/0x270
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x21f/0x3c0
 __netif_receive_skb+0xd3/0x370
 netif_receive_skb+0x1bb/0x790
 NF_HOOK+0xa4/0x3a0
 br_handle_frame_finish+0x14b2/0x1b40
 br_nf_hook_thresh+0x3dd/0x4c0
 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70
 br_nf_pre_routing_ipv6+0x374/0x6f0
 br_handle_frame+0x989/0x1520
 __netif_receive_skb_core+0x98f/0x30a0
 __netif_receive_skb+0x72/0x370
 process_backlog+0x633/0x1500
 __napi_poll+0xae/0x320
 net_rx_action+0x6d2/0xec0
 handle_softirqs+0x27c/0x850
 do_softirq+0xf9/0x1a0
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x189/0x1d0
 batadv_tt_purge+0x4d1/0x9e0
 process_scheduled_works+0xaec/0x17a0
 worker_thread+0x89f/0xd90
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 ret_from_fork_asm+0x1a/0x30
 </TASK>
