WARNING: CPU: 0 PID: 3070 at kernel/kthread.c:87 free_kthread_struct+0xa2/0xe0 kernel/kthread.c:87
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 3070 Comm: syz-executor4 Not tainted 4.14.0-rc7-next-20171102+ #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1c4/0x1e0 kernel/panic.c:546
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:177
 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:260
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:free_kthread_struct+0xa2/0xe0 kernel/kthread.c:87
RSP: 0018:ffff8801db207768 EFLAGS: 00010206
RAX: ffff8801ccfb2100 RBX: ffff8801cca7a540 RCX: ffffffff814937d2
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8801cca7a6c8
RBP: ffff8801db207770 R08: ffffffff85f3b680 R09: 1ffff1003b640ed4
R10: ffff8801ccfb2100 R11: 0000000000000002 R12: 1ffff1003b640ef0
R13: 1ffff1003b640ef4 R14: 0000000000000000 R15: ffff8801db2077e0
 free_task+0x134/0x1a0 kernel/fork.c:390
 __put_task_struct+0x229/0x3b0 kernel/fork.c:663
 put_task_struct include/linux/sched/task.h:95 [inline]
 delayed_put_task_struct+0xca/0x3d0 kernel/exit.c:180
 __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
 rcu_do_batch kernel/rcu/tree.c:2676 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2935 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2902 [inline]
 rcu_process_callbacks+0xd74/0x17d0 kernel/rcu/tree.c:2919
 __do_softirq+0x29d/0xbb2 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d3/0x210 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:540 [inline]
 smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:770
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:93
RSP: 0018:ffff8801cd597408 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
RAX: dffffc0000000000 RBX: ffff8801cd5d7988 RCX: ffffffff8502b708
RDX: 1ffff10039abaf31 RSI: ffff8801cd5d7988 RDI: ffff8801cd5d7990
RBP: ffff8801cd597458 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff8744cca0 R12: ffff8801cd5d7988
R13: ffff8801cd5d7988 R14: ffff8801cd5d7988 R15: dffffc0000000000
 plist_check_list+0x46/0xa0 lib/plist.c:49
 plist_check_head+0xd5/0x130 lib/plist.c:60
 plist_del+0xd7/0x990 lib/plist.c:115
 __unqueue_futex+0x1b6/0x290 kernel/futex.c:1391
 mark_wake_futex+0x129/0x1c0 kernel/futex.c:1413
 futex_wake+0x53c/0x680 kernel/futex.c:1567
 do_futex+0x1034/0x20d0 kernel/futex.c:3487
 SYSC_futex kernel/futex.c:3543 [inline]
 SyS_futex+0x260/0x390 kernel/futex.c:3511
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x452869
RSP: 002b:00007ffd05169428 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000758048 RCX: 0000000000452869
RDX: 000000000000001e RSI: 0000000000000001 RDI: 0000000000758048
RBP: 0000000000000086 R08: 00000000007609c0 R09: 0000000000000000
R10: 00007ffd05169500 R11: 0000000000000246 R12: fffffffffffffffe
R13: 000000002001d000 R14: 0000000000016df8 R15: 0000000000000016
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..