SELinux: unrecognized netlink message: protocol=4 nlmsg_type=0 sclass=netlink_tcpdiag_socket
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=0 sclass=netlink_tcpdiag_socket
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=0 sclass=netlink_tcpdiag_socket
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=0 sclass=netlink_tcpdiag_socket
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=0 sclass=netlink_tcpdiag_socket
INFO: task init:21855 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D ffff8801d0887718 29280 21855      1 0x00000000
 ffff8801d0887718 ffff8801d2be8000 08578aba186e52f4 ffff8801d2be8000
 0000000000000000 ffff8801d2be8800 ffff8801db61f180 ffff8801db61f1a8
 ffff8801db61e898 ffff8801c0fbc740 ffff8801d2be8000 ffffed003a110001
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
 [<ffffffff81c8b2aa>] tty_open+0x56a/0xf50 drivers/tty/tty_io.c:2067
 [<ffffffff814a3ec0>] chrdev_open+0x230/0x630 fs/char_dev.c:388
 [<ffffffff8149154f>] do_dentry_open+0x38f/0xbd0 fs/open.c:749
 [<ffffffff81494d3b>] vfs_open+0x10b/0x210 fs/open.c:862
 [<ffffffff814c5ddf>] do_last fs/namei.c:3269 [inline]
 [<ffffffff814c5ddf>] path_openat+0x136f/0x4470 fs/namei.c:3406
 [<ffffffff814ccab1>] do_filp_open+0x1a1/0x270 fs/namei.c:3440
 [<ffffffff81495668>] do_sys_open+0x2f8/0x600 fs/open.c:1038
 [<ffffffff8149599d>] SYSC_open fs/open.c:1056 [inline]
 [<ffffffff8149599d>] SyS_open+0x2d/0x40 fs/open.c:1051
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
1 lock held by init/21855:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81c8b2aa>] tty_open+0x56a/0xf50 drivers/tty/tty_io.c:2067
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 3640 Comm: syz-executor.5 Not tainted 4.4.174+ #4
task: ffff8801d21d5f00 task.stack: ffff8801d2b08000
RIP: 0010:[<ffffffff81309616>]  [<ffffffff81309616>] __sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:100
RSP: 0018:ffff8801d2b0fa38  EFLAGS: 00000246
RAX: ffff8801d21d5f00 RBX: 0000000000000000 RCX: ffffc90005129000
RDX: 0000000000000002 RSI: ffffffff821d9856 RDI: ffff8801d2b0fdc8
RBP: ffff8801d2b0fa38 R08: ffff8801d2b0fe00 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d2b0fd80
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f191d1f4700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000007358a8 CR3: 00000001d8043000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d2b0faa0 ffffffff821d9856 0000000000000000 00000000d2b0fa68
 0000000000000000 ffff8801d2b0fb10 0000000000000000 ffff8801d2b0fd88
 0000000000000000 ffff8801d2b0fd80 000000002000b8c0 1ffff1003a561f5c
Call Trace:
 [<ffffffff821d9856>] copy_msghdr_from_user+0x2a6/0x550 net/socket.c:1894
 [<ffffffff821d9c03>] ___sys_sendmsg+0x103/0x890 net/socket.c:1923
 [<ffffffff821dd2e0>] __sys_sendmmsg+0x130/0x2e0 net/socket.c:2060
 [<ffffffff821dd4c5>] SYSC_sendmmsg net/socket.c:2090 [inline]
 [<ffffffff821dd4c5>] SyS_sendmmsg+0x35/0x60 net/socket.c:2085
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Code: fe ff ff 66 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 80 67 01 00 65 8b 15 08 d1 d0 7e 81 e2 00 01 1f 00 75 2b 8b 90 50 12 00 00 <83> fa 02 75 20 48 8b 88 58 12 00 00 8b 80 54 12 00 00 48 8b 11 
NMI backtrace for cpu 1
CPU: 1 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #4
task: ffff8801da6f2f80 task.stack: ffff8801d9ed8000
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:ffff8801d9edfc88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8801d9edfcb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000070fbb4 CR3: 00000000b8cf6000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8801d9edfcd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8801d9edfd30 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