IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
WARNING: CPU: 1 PID: 4511 at kernel/signal.c:351 task_participate_group_stop+0x205/0x260 kernel/signal.c:351
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4511 Comm: 3 Not tainted 4.17.0-rc3+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 panic+0x22f/0x4de kernel/panic.c:184
 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:task_participate_group_stop+0x205/0x260 kernel/signal.c:351
RSP: 0018:ffff8801b31d7830 EFLAGS: 00010093
RAX: ffff8801cee36100 RBX: 0000000000000000 RCX: ffffffff81498cfb
RDX: 0000000000000000 RSI: ffffffff81498e15 RDI: 0000000000000005
RBP: ffff8801b31d7850 R08: ffff8801cee36100 R09: ffffed003b2e3d19
R10: ffffed003b2e3d19 R11: ffff8801d971e8cb R12: ffff8801aed9da58
R13: ffff8801aed9d9c0 R14: 0000000000040000 R15: dffffc0000000000
 do_signal_stop+0x502/0xa20 kernel/signal.c:2176
 get_signal+0x9b4/0x1960 kernel/signal.c:2353
 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
 do_syscall_32_irqs_on arch/x86/entry/common.c:338 [inline]
 do_fast_syscall_32+0xcc3/0xf9b arch/x86/entry/common.c:394
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0033:0x127
RSP: 002b:00007ffdd7c294b0 EFLAGS: 00000200 ORIG_RAX: 000000000000003b
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..