INFO: task syz-executor.4:13832 blocked for more than 145 seconds.
      Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:24112 pid:13832 tgid:13831 ppid:5083   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x17df/0x4a40 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6804 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6819
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 __flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617
 rds_tcp_listen_stop+0x145/0x170 net/rds/tcp_listen.c:347
 rds_tcp_kill_sock net/rds/tcp.c:614 [inline]
 rds_tcp_exit_net+0x139/0x660 net/rds/tcp.c:637
 ops_exit_list net/core/net_namespace.c:170 [inline]
 setup_net+0x8d3/0xbc0 net/core/net_namespace.c:362
 copy_net_ns+0x4e4/0x7b0 net/core/net_namespace.c:495
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 copy_namespaces+0x41a/0x490 kernel/nsproxy.c:179
 copy_process+0x1928/0x3db0 kernel/fork.c:2522
 kernel_clone+0x21e/0x8d0 kernel/fork.c:2924
 __do_sys_clone kernel/fork.c:3067 [inline]
 __se_sys_clone kernel/fork.c:3051 [inline]
 __x64_sys_clone+0x258/0x2a0 kernel/fork.c:3051
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f99c507dda9
RSP: 002b:00007f99c5daa078 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f99c51abf80 RCX: 00007f99c507dda9
RDX: 0000000020000340 RSI: 0000000020000320 RDI: 0000000044241000
RBP: 00007f99c50ca47a R08: 00000000200003c0 R09: 00000000200003c0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 000000000000000b R14: 00007f99c51abf80 R15: 00007ffd25d9df38
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:1/11:
 #0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #1: ffffc90000107d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #1: ffffc90000107d20 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #2: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf5/0xb90 net/core/net_namespace.c:580
1 lock held by khungtaskd/29:
 #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
2 locks held by kworker/u4:7/2422:
2 locks held by getty/4830:
 #0: ffff88802e60a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
3 locks held by kworker/1:5/5141:
 #0: ffff888014c7cd48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #0: ffff888014c7cd48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #1: ffffc900045dfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #1: ffffc900045dfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #2: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281
2 locks held by kworker/u4:9/5412:
 #0: ffff888014c89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #0: ffff888014c89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #1: ffffc90009c87d20 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #1: ffffc90009c87d20 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
1 lock held by syz-executor.4/13832:
 #0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
1 lock held by syz-executor.4/14372:
 #0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
3 locks held by syz-executor.0/15167:
 #0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
 #1: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xce/0x370 net/ipv4/ip_tunnel.c:1139