INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:0     pid:9     ppid:2      flags:0x00000008
Workqueue: events_unbound linkwatch_event
Call trace:
 __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0xdb4/0x1a6c kernel/sched/core.c:6563
 schedule+0xc4/0x170 kernel/sched/core.c:6639
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6698
 __mutex_lock_common+0xb20/0x1f3c kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
 linkwatch_event+0x14/0x68 net/core/link_watch.c:263
 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
INFO: task kworker/u4:1:11 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:0     pid:11    ppid:2      flags:0x00000008
Workqueue: netns cleanup_net
Call trace:
 __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0xdb4/0x1a6c kernel/sched/core.c:6563
 schedule+0xc4/0x170 kernel/sched/core.c:6639
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6698
 __mutex_lock_common+0xb20/0x1f3c kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
 ip_tunnel_delete_nets+0xc8/0x334 net/ipv4/ip_tunnel.c:1152
 ipgre_exit_batch_net+0x30/0x40 net/ipv4/ip_gre.c:1040
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x650/0xa90 net/core/net_namespace.c:640
 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
INFO: task kworker/0:1:14 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1     state:D stack:0     pid:14    ppid:2      flags:0x00000008
Workqueue: ipv6_addrconf addrconf_dad_work
Call trace:
 __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0xdb4/0x1a6c kernel/sched/core.c:6563
 schedule+0xc4/0x170 kernel/sched/core.c:6639
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6698
 __mutex_lock_common+0xb20/0x1f3c kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
 addrconf_dad_work+0xc0/0x10a0 net/ipv6/addrconf.c:4138
 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
INFO: task kworker/1:3:4355 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D stack:0     pid:4355  ppid:2      flags:0x00000008
Workqueue: ipv6_addrconf addrconf_dad_work
Call trace:
 __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0xdb4/0x1a6c kernel/sched/core.c:6563
 schedule+0xc4/0x170 kernel/sched/core.c:6639
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6698
 __mutex_lock_common+0xb20/0x1f3c kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
 addrconf_dad_work+0xc0/0x10a0 net/ipv6/addrconf.c:4138
 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff80001cb37c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
4 locks held by kworker/u4:1/11:
 #0: ffff0000c0845138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff80001cb57c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff8000179f85d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x144/0xa90 net/core/net_namespace.c:594
 #3: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015557db0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffff8000155585d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517
3 locks held by kworker/0:1/14:
 #0: ffff0000d5d5fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff80001cb87c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by khungtaskd/28:
 #0: ffff800015557440 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
3 locks held by kworker/0:2/3778:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff800023fc7c40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
2 locks held by getty/4081:
 #0: ffff0000d62ff098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff800020b5e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2e8/0xfa8 drivers/tty/n_tty.c:2198
3 locks held by kworker/1:3/4355:
 #0: ffff0000d5d5fd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff800021147c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by syz.0.17/4520:
3 locks held by kworker/u4:6/4521:
 #0: ffff0000c002a138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff800021607c40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by syz-executor/4523:
 #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x64c/0xcc4 net/core/rtnetlink.c:6163
1 lock held by syz-executor/4535:
 #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x64c/0xcc4 net/core/rtnetlink.c:6163
1 lock held by syz-executor/4546:
 #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff800017a04e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x64c/0xcc4 net/core/rtnetlink.c:6163

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