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WARNING: CPU: 0 PID: 4321 at kernel/signal.c:343 task_participate_group_stop+0x220/0x2c0 kernel/signal.c:343
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 4321 Comm: 3 Not tainted 4.9.96-g71fce1e #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d7f47ab0 ffffffff81eb0b69 ffffffff83a484a0 00000000ffffffff
 0000000000000000 0000000000000000 0000000000000157 ffff8801d7f47b70
 ffffffff8141f975 0000000041b58ab3 ffffffff841b8030 ffffffff8141f7b6
Call Trace:
 [<ffffffff81eb0b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8141f975>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff8141fc61>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff8113461c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff8115ec40>] task_participate_group_stop+0x220/0x2c0 kernel/signal.c:343
 [<ffffffff81163333>] do_signal_stop+0x373/0x7c0 kernel/signal.c:2024
 [<ffffffff81167c78>] get_signal+0x5b8/0x1450 kernel/signal.c:2201
 [<ffffffff810524d7>] do_signal+0x87/0x19f0 arch/x86/kernel/signal.c:807
 [<ffffffff81005581>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:157
 [<ffffffff810064d4>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810064d4>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810064d4>] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287
 [<ffffffff839f3313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..