INFO: task syz-executor.5:27895 blocked for more than 140 seconds.
      Not tainted 4.9.171+ #49
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28776 27895      1 0x00000004
 ffff88017ce0af80 ffff880175477900 ffff8801db721000 ffff880181272f80
 ffff8801db721018 ffff8801acb8fc08 ffffffff82801dde ffffffff82e5187e
 ffffffff819fa860 000000000000001e ffff8801db7218f0 1ffff10035971f70
Call Trace:
 [<00000000305c8751>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<00000000bdbcd7a5>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<00000000026d7d4b>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<00000000026d7d4b>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<000000008135f3b2>] copy_net_ns+0x15b/0x340 net/core/net_namespace.c:407
 [<00000000a674df5a>] create_new_namespaces+0x37c/0x7a0 kernel/nsproxy.c:106
 [<000000002a55849f>] unshare_nsproxy_namespaces+0xab/0x1e0 kernel/nsproxy.c:205
 [<0000000072dfd2b3>] SYSC_unshare kernel/fork.c:2276 [inline]
 [<0000000072dfd2b3>] SyS_unshare+0x305/0x6f0 kernel/fork.c:2226
 [<000000008cceb5ed>] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285
 [<0000000056231b7f>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<000000005c5d86ba>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<000000005c5d86ba>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<0000000006b8fabc>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
2 locks held by getty/2024:
 #0:  (&tty->ldisc_sem){++++++}, at: [<000000007db245cf>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<00000000abe47605>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
3 locks held by kworker/u4:4/2257:
 #0:  ("%s""netns"){.+.+.+}, at: [<00000000694b4ce7>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107
 #1:  (net_cleanup_work){+.+.+.}, at: [<000000006e2e9551>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111
 #2:  (net_mutex){+.+.+.}, at: [<000000009f002122>] cleanup_net+0x131/0x8a0 net/core/net_namespace.c:440
1 lock held by syz-executor.5/27895:
 #0:  (net_mutex){+.+.+.}, at: [<000000008135f3b2>] copy_net_ns+0x15b/0x340 net/core/net_namespace.c:407
1 lock held by syz-executor.2/13800:
 #0:  (net_mutex){+.+.+.}, at: [<000000008135f3b2>] copy_net_ns+0x15b/0x340 net/core/net_namespace.c:407
1 lock held by syz-executor.3/19619:
 #0:  (net_mutex){+.+.+.}, at: [<000000008135f3b2>] copy_net_ns+0x15b/0x340 net/core/net_namespace.c:407

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