INFO: task syz-executor.4:17055 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 ffff8801ba6179d8 28360 17055  17051 0x00000000
 ffff8801ba6179d8 ffff8800b53d4740 754fd6a8f12fad35 ffff8800b53d4740
 0000000000000000 ffff8800b53d5000 ffff8801db71f180 ffff8801db71f1a8
 ffff8801db71e898 ffff8801bcdfdf00 ffff8800b53d4740 ffffed00374c2001
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.4/17055:
 #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: ffff8801da6c4740 task.stack: ffff8800001c0000
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:ffff8800001c7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001c7cb8 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: 0000000020000080 CR3: 000000009a2a0000 CR4: 00000000001606b0
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001c7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001c7d30 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: 1927 Comm: rsyslogd Not tainted 4.4.174+ #4
task: ffff8801d6e1c740 task.stack: ffff8800b8f20000
RIP: 0010:[<ffffffff8112f51c>]  [<ffffffff8112f51c>] core_kernel_text kernel/extable.c:75 [inline]
RIP: 0010:[<ffffffff8112f51c>]  [<ffffffff8112f51c>] __kernel_text_address+0x3c/0xa0 kernel/extable.c:101
RSP: 0018:ffff8800b8f277a8  EFLAGS: 00000202
RAX: 0000000000000007 RBX: 0000000000000246 RCX: 1ffffffff0634400
RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
RBP: ffff8800b8f277b0 R08: ffff8800b8f278c0 R09: 0000000000000000
R10: ffff8800b8f27ae8 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8800b8f278c0 R14: ffff8800b8f27ff8 R15: ffff8800b8f20000
FS:  00007fe9422e2700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000a6fd78 CR3: 00000001d77bc000 CR4: 00000000001606b0
Stack:
 ffff8800b8f27aa0 ffff8800b8f27808 ffffffff81013549 0000000000000246
 ffff8800b8f27ae8 ffff8800b8f27ae8 ffffffff8280f0b0 ffff8800b8f278c0
 ffffffff8280f0b0 ffff8800b8f27860 ffff8801db707fc0 0000000000000000
Call Trace:
 [<ffffffff81013549>] print_context_stack+0x59/0xd0 arch/x86/kernel/dumpstack.c:107
 [<ffffffff81012bb9>] dump_trace+0x179/0x390 arch/x86/kernel/dumpstack_64.c:243
 [<ffffffff8102e3c6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff81483f22>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff81483f22>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff81483f22>] kasan_kmalloc.part.0+0x62/0xf0 mm/kasan/kasan.c:616
 [<ffffffff81484197>] kasan_kmalloc+0xb7/0xd0 mm/kasan/kasan.c:601
 [<ffffffff8148475f>] kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:554
 [<ffffffff81480160>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff81480160>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff81480160>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff81480160>] kmem_cache_alloc_trace+0xe0/0x2d0 mm/slub.c:2640
 [<ffffffff8121efdc>] kmalloc include/linux/slab.h:476 [inline]
 [<ffffffff8121efdc>] syslog_print kernel/printk/printk.c:1153 [inline]
 [<ffffffff8121efdc>] do_syslog kernel/printk/printk.c:1336 [inline]
 [<ffffffff8121efdc>] do_syslog+0x5bc/0xaf0 kernel/printk/printk.c:1306
 [<ffffffff81608274>] kmsg_read+0x74/0xa0 fs/proc/kmsg.c:39
 [<ffffffff815e03bd>] proc_reg_read+0xfd/0x180 fs/proc/inode.c:202
 [<ffffffff81496556>] __vfs_read+0x116/0x3c0 fs/read_write.c:434
 [<ffffffff81498264>] vfs_read+0x134/0x360 fs/read_write.c:456
 [<ffffffff8149aa8c>] SYSC_read fs/read_write.c:571 [inline]
 [<ffffffff8149aa8c>] SyS_read+0xdc/0x1c0 fs/read_write.c:564
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Code: 48 81 ff c1 df 71 82 72 6c 48 c7 c0 04 20 1a 83 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 <38> d0 7c 04 84 d2 75 4a 8b 05 da 2a 07 02 85 c0 75 12 48 81 fb