WARNING: CPU: 0 PID: 18169 at kernel/fork.c:718 __put_task_struct+0x3ef/0x620 kernel/fork.c:718
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 18169 Comm: syz-executor2 Not tainted 4.19.0-rc7-next-20181008+ #89
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+0x244/0x3ab lib/dump_stack.c:113
 panic+0x238/0x4e7 kernel/panic.c:184
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:__put_task_struct+0x3ef/0x620 kernel/fork.c:718
Code: 4c 89 ee e8 d3 9d 7b 00 e9 a1 fe ff ff e8 89 53 37 00 0f 0b e9 7c fd ff ff e8 7d 53 37 00 0f 0b e9 87 fd ff ff e8 71 53 37 00 <0f> 0b e9 d0 fc ff ff e8 65 53 37 00 49 8d 87 90 05 00 00 31 f6 48
RSP: 0018:ffff88017da26fb0 EFLAGS: 00010093
RAX: ffff880182176300 RBX: ffff880182176300 RCX: ffffffff8147298d
RDX: 0000000000000000 RSI: ffffffff81472cbf RDI: 0000000000000005
RBP: ffff88017da27090 R08: ffff880182176300 R09: ffffed003042ec64
R10: ffffed003042ec64 R11: ffff880182176323 R12: 1ffff1002fb44df9
R13: 0000000000000000 R14: ffff88017da27068 R15: ffff8801ccc48ac0
 put_task_struct include/linux/sched/task.h:96 [inline]
 perf_event_exit_task_context kernel/events/core.c:11079 [inline]
 perf_event_exit_task+0xca6/0x1070 kernel/events/core.c:11128
 do_exit+0xf8c/0x2610 kernel/exit.c:876
 do_group_exit+0x177/0x440 kernel/exit.c:970
 get_signal+0x8a8/0x1970 kernel/signal.c:2517
 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: Bad RIP value.
RSP: 002b:00007f7010303cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000072bf08 RCX: 0000000000457579
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c
R13: 00007ffec56d4cbf R14: 00007f70103049c0 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..