INFO: task syz-executor.4:11568 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D ffff88009cf779d8 27512 11568  11567 0x00000000
 ffff88009cf779d8 ffff8801b1e2df00 c60703fbd3b8eb09 ffff8801b1e2df00
 0000000000000000 ffff8801b1e2e700 ffff8801db71f180 ffff8801db71f1a8
 ffff8801db71e898 ffff8801d0e6df00 ffff8801b1e2df00 ffffed00139ee001
Call Trace:
 [<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
 [<ffffffff8270a333>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388
 [<ffffffff8270c492>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8270c492>] mutex_lock_nested+0x3c2/0xb80 kernel/locking/mutex.c:621
 [<ffffffff8221b16a>] copy_net_ns+0xca/0x250 net/core/net_namespace.c:387
 [<ffffffff81136a90>] create_new_namespaces+0x2f0/0x670 kernel/nsproxy.c:95
 [<ffffffff8113709a>] copy_namespaces+0x28a/0x320 kernel/nsproxy.c:150
 [<ffffffff810cd012>] copy_process+0x2472/0x68a0 kernel/fork.c:1522
 [<ffffffff810d186e>] _do_fork+0x14e/0xdc0 kernel/fork.c:1806
 [<ffffffff810d25b7>] SYSC_clone kernel/fork.c:1917 [inline]
 [<ffffffff810d25b7>] SyS_clone+0x37/0x50 kernel/fork.c:1911
 [<ffffffff82718cb7>] tracesys+0x88/0x8d
1 lock held by syz-executor.4/11568:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff8221b16a>] copy_net_ns+0xca/0x250 net/core/net_namespace.c:387
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #4
task: ffff8801da6f4740 task.stack: ffff8800001d0000
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800001d7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001d7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000940004 CR3: 000000009f3a9000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001d7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001d7d30 ffffffff81ab8252
Call Trace:
 [<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae lib/nmi_backtrace.c:85
 [<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813b4762>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1 
NMI backtrace for cpu 1
CPU: 1 PID: 2148 Comm: syz-executor.5 Not tainted 4.4.174+ #4
task: ffff8801d50d5f00 task.stack: ffff8801b6b60000
RIP: 0010:[<ffffffff811ffb43>]  [<ffffffff811ffb43>] __lock_acquire+0x593/0x4f50 kernel/locking/lockdep.c:3072
RSP: 0018:ffff8801b6b67870  EFLAGS: 00000087
RAX: 0000000000000002 RBX: 00000000000d201d RCX: 0000000000000001
RDX: 1ffff1003aa1acf8 RSI: 0000000000000001 RDI: ffff8801d50d6811
RBP: ffff8801b6b679e8 R08: 0000000000000001 R09: ffff8801d50d6810
R10: ffffffff82836880 R11: 0000000000000000 R12: ffff8801d50d5f00
R13: ffff8801d50d67f0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000ed3940(0063) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006cb300 CR3: 00000001d0db0000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 0000000000000000 0000000000000000 ffff8801b6b67a08 0000000000000046
 ffff8801d50d6808 ffff8801d50d67c0 ffff8801d50d6810 000001ea00000001
 ffff8801d50d6808 ffff8801d50d67c0 ffff8801d50d6810 1ffff10000000000
Call Trace:
 [<ffffffff81205f6e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592
 [<ffffffff81956476>] rcu_lock_acquire include/linux/rcupdate.h:477 [inline]
 [<ffffffff81956476>] rcu_read_lock include/linux/rcupdate.h:861 [inline]
 [<ffffffff81956476>] avc_has_perm_noaudit security/selinux/avc.c:1108 [inline]
 [<ffffffff81956476>] avc_has_perm+0xe6/0x3a0 security/selinux/avc.c:1146
 [<ffffffff819633a0>] task_has_perm+0x200/0x330 security/selinux/hooks.c:1525
 [<ffffffff819634f4>] selinux_task_wait+0x24/0x30 security/selinux/hooks.c:3763
 [<ffffffff8194fcc3>] security_task_wait+0x73/0xb0 security/security.c:993
 [<ffffffff810db16b>] wait_consider_task+0x28b/0x35b0 kernel/exit.c:1334
 [<ffffffff810de7e0>] do_wait_thread kernel/exit.c:1447 [inline]
 [<ffffffff810de7e0>] do_wait+0x350/0xa00 kernel/exit.c:1518
 [<ffffffff810df714>] SYSC_wait4 kernel/exit.c:1649 [inline]
 [<ffffffff810df714>] SyS_wait4+0x144/0x210 kernel/exit.c:1614
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Code: d0 7c 08 84 d2 0f 85 97 3a 00 00 8b 05 57 7f e5 02 85 c0 89 84 24 80 00 00 00 0f 84 cc db 1a 00 c7 84 24 80 00 00 00 00 00 00 00 <48> b8 00 00 00 00 00 fc ff df 48 03 44 24 78 48 c7 00 00 00 00