INFO: task kworker/u4:0:16861 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:0    D26048 16861      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common+0x29c/0x470 kernel/sched/completion.c:115
 flush_workqueue+0x40b/0x13e0 kernel/workqueue.c:2713
 rxrpc_release_sock net/rxrpc/af_rxrpc.c:906 [inline]
 rxrpc_release+0x25b/0x530 net/rxrpc/af_rxrpc.c:936
 __sock_release net/socket.c:599 [inline]
 sock_release+0x87/0x1d0 net/socket.c:619
 afs_close_socket+0x1c7/0x320 fs/afs/rxrpc.c:119
 afs_net_exit+0x1c1/0x310 fs/afs/main.c:155
 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153
 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Showing all locks held in the system:
1 lock held by khungtaskd/1570:
 #0: 000000001110e5f0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7770:
 #0: 0000000069102e6b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
3 locks held by kworker/0:8/3845:
 #0: 00000000b7b4e489 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
 #1: 00000000f3a1c0be ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
 #2: 00000000df242445 (rtnl_mutex){+.+.}, at: addrconf_dad_work+0x9c/0x10a0 net/ipv6/addrconf.c:3989
5 locks held by kworker/1:0/15530:
3 locks held by kworker/u4:0/16861:
 #0: 000000005400fa4f ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
 #1: 00000000fc12e9eb (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
 #2: 000000000f5e1816 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521
2 locks held by kworker/0:1/19407:
 #0: 00000000e1c1806f ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
 #1: 000000002c55fd76 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
3 locks held by kworker/0:4/3251:
 #0: 00000000a99af819 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
 #1: 000000008b5a02b8 ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
 #2: 00000000df242445 (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236
1 lock held by syz-executor.1/13257:
 #0: 00000000df242445 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
 #0: 00000000df242445 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779
2 locks held by syz-executor.5/13254:
 #0: 00000000df242445 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
 #0: 00000000df242445 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779
 #1: 00000000c1b53739 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #1: 00000000c1b53739 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667
1 lock held by syz-executor.3/13266:
 #0: 00000000df242445 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
 #0: 00000000df242445 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779
1 lock held by syz-executor.4/13274:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 15530 Comm: kworker/1:0 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: events macvlan_process_broadcast
RIP: 0010:find_match.part.0+0x10a/0x1530 net/ipv6/route.c:673
Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 5d 0e 00 00 45 8b b6 3c 02 00 00 <31> ff 44 89 f6 e8 ac ff 5a fa 45 85 f6 74 66 e8 32 fe 5a fa 48 8d
RSP: 0018:ffff8880ba107680 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff8880936cc680 RCX: ffffffff87079192
RDX: 0000000000000000 RSI: ffffffff870786f2 RDI: ffff8880ae894fbc
RBP: ffff8880ba107728 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000003
R13: 0000000000000242 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f945dd85000 CR3: 0000000009e6d000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 find_match net/ipv6/route.c:670 [inline]
 find_rr_leaf net/ipv6/route.c:719 [inline]
 rt6_select net/ipv6/route.c:769 [inline]
 fib6_table_lookup+0x4c2/0xf40 net/ipv6/route.c:1876
 ip6_pol_route+0x180/0x1270 net/ipv6/route.c:1909
 fib6_rule_lookup+0x10b/0x4e0 net/ipv6/fib6_rules.c:118
 ip6_route_input_lookup net/ipv6/route.c:1990 [inline]
 ip6_route_input+0x6c0/0xaa0 net/ipv6/route.c:2125
 ip6_rcv_finish_core.constprop.0.isra.0+0xd7/0x550 net/ipv6/ip6_input.c:63
 ip6_rcv_finish+0x176/0x2f0 net/ipv6/ip6_input.c:74
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ipv6_rcv+0xf2/0x3f0 net/ipv6/ip6_input.c:273
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:4954
 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5066
 process_backlog+0x241/0x700 net/core/dev.c:5849
 napi_poll net/core/dev.c:6280 [inline]
 net_rx_action+0x4ac/0xfb0 net/core/dev.c:6346
 __do_softirq+0x265/0x980 kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1092
 </IRQ>
 do_softirq.part.0+0x160/0x1c0 kernel/softirq.c:336
 netif_rx_ni+0x203/0x350 net/core/dev.c:4529
 macvlan_broadcast+0x1a7/0x6e0 drivers/net/macvlan.c:291
 macvlan_process_broadcast+0x47a/0x620 drivers/net/macvlan.c:325
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415