pktgen: kernel_thread() failed for cpu 0
pktgen: Cannot create thread for cpu 0 (-4)
pktgen: kernel_thread() failed for cpu 1
pktgen: Cannot create thread for cpu 1 (-4)
pktgen: Initialization failed for all threads
INFO: task syz-executor7:10295 blocked for more than 120 seconds.
      Not tainted 4.4.133-g54f36ea #52
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D ffff8801cd8efbb8 29792 10295   3824 0x00000004
 ffff8801cd8efbb8 0000000000000000 ffff8800b9a120e0 ffffed001734241b
 ffff8800b9a11800 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8
 ffff8801db21f4c0 ffff8800b6d33000 ffff8800b9a11800 0000000000000000
Call Trace:
 [<ffffffff838b2f2a>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838b36c3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392
 [<ffffffff838b9807>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838b9807>] mutex_lock_nested+0x307/0x850 kernel/locking/mutex.c:621
 [<ffffffff815840be>] lock_mount+0x8e/0x2c0 fs/namespace.c:2054
 [<ffffffff81587ead>] do_loopback fs/namespace.c:2187 [inline]
 [<ffffffff81587ead>] do_mount+0x96d/0x2860 fs/namespace.c:2827
 [<ffffffff8158a7b0>] SYSC_mount fs/namespace.c:3027 [inline]
 [<ffffffff8158a7b0>] SyS_mount+0x130/0x1d0 fs/namespace.c:3005
 [<ffffffff838c0f65>] entry_SYSCALL_64_fastpath+0x22/0x9e
1 lock held by syz-executor7/10295:
 #0:  (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff815840be>] lock_mount+0x8e/0x2c0 fs/namespace.c:2054
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 492 Comm: khungtaskd Not tainted 4.4.133-g54f36ea #52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bad44800 task.stack: ffff8801d8c48000
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8801d8c4fcc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8801d8c4fcf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f7a0
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c96707000 CR3: 00000000b462d000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f7a0 ffffffff84a18ae0 0000000000000007 fffffbfff0942c0c
 0000000000000040 ffff8801d8c4fd10 ffffffff810b5dd1 ffffffff83c0b220
 0000000000000003 ffff8801d8c4fd68 ffffffff81e19543 ffffffff8140db2f
Call Trace:
 [<ffffffff810b5dd1>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e19543>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5e74>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a219>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a219>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a219>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a219>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190818>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c1395>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 b2 
NMI backtrace for cpu 1
CPU: 1 PID: 10294 Comm: syz-executor7 Not tainted 4.4.133-g54f36ea #52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b9a10000 task.stack: ffff8801d1280000
RIP: 0010:[<ffffffff815b2312>]  [<ffffffff815b2312>] do_make_slave fs/pnode.c:83 [inline]
RIP: 0010:[<ffffffff815b2312>]  [<ffffffff815b2312>] change_mnt_propagation+0xe2/0xb70 fs/pnode.c:130
RSP: 0018:ffff8801d1287b08  EFLAGS: 00000246
RAX: 1ffff100362323d6 RBX: ffff8801d6fbe600 RCX: ffffc90005b44000
RDX: 0000000000040000 RSI: ffffffff815b22f0 RDI: ffff8801b1191eb0
RBP: ffff8801d1287b60 R08: ffff8801d6fbe668 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8800b9a10000 R12: ffff8801b1191e00
R13: 0000000000040000 R14: dffffc0000000000 R15: ffff8800b0f8a8b0
FS:  00007f7474a45700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c952ea140 CR3: 00000001d6a0e000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8157df7d ffff8801d6fbe600 0000000000000000 ffff8801d6fbe620
 ffff8801d6fbe6e0 ffffed003adf7cc4 ffff8801d6fbe690 dffffc0000000000
 ffff8801d6fbe600 ffff8800af661340 ffff8801d1287c00 ffff8801d1287c28
Call Trace:
 [<ffffffff8157e696>] umount_tree+0x326/0x810 fs/namespace.c:1501
 [<ffffffff81586a8c>] attach_recursive_mnt+0x74c/0x8e0 fs/namespace.c:2035
 [<ffffffff81586d8f>] graft_tree+0x16f/0x1f0 fs/namespace.c:2099
 [<ffffffff81589628>] do_loopback fs/namespace.c:2220 [inline]
 [<ffffffff81589628>] do_mount+0x20e8/0x2860 fs/namespace.c:2827
 [<ffffffff8158a7b0>] SYSC_mount fs/namespace.c:3027 [inline]
 [<ffffffff8158a7b0>] SyS_mount+0x130/0x1d0 fs/namespace.c:3005
 [<ffffffff838c0f65>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: 13 02 00 00 e8 50 f0 d9 ff 49 8d bc 24 b0 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 30 00 0f 85 41 08 00 00 4d 8b bc 24 b0 00 00 00 <49> 8d 97 50 ff ff ff 48 39 d3 49 89 d4 75 90 48 89 55 d0 e8 16