INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 1 PID: 3118 Comm: syz-fuzzer Not tainted 4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xe9/0x14b lib/dump_stack.c:53
 register_lock_class+0x164/0x5d0 kernel/locking/lockdep.c:752
 __lock_acquire+0xb4/0x1430 kernel/locking/lockdep.c:3314
 lock_acquire+0xbf/0x220 kernel/locking/lockdep.c:3914
 __raw_write_lock include/linux/rwlock_api_smp.h:210 [inline]
 _raw_write_lock+0x2a/0x40 kernel/locking/spinlock.c:288
 neigh_timer_handler+0x2d/0x3e0 net/core/neighbour.c:913
 call_timer_fn+0x9f/0x3f0 kernel/time/timer.c:1320
 expire_timers kernel/time/timer.c:1357 [inline]
 __run_timers kernel/time/timer.c:1660 [inline]
 run_timer_softirq+0x68a/0x830 kernel/time/timer.c:1686
 __do_softirq+0xcb/0x4f3 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0xd4/0xe0 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:540 [inline]
 smp_apic_timer_interrupt+0x8e/0x2a0 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:920
 </IRQ>
RIP: 0033:0x40cd5d
RSP: 002b:000000c444a695a8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff11
RAX: 000000c44523de00 RBX: 000000002902f408 RCX: 0000000000000000
RDX: 000000c44523de00 RSI: 000000000000ffff RDI: 0000000000000000
RBP: 000000c444a695c0 R08: 000000000000000b R09: 000000c42001a228
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000000fb R14: 00000000000000fb R15: 000000000000000e
BUG: unable to handle kernel NULL pointer dereference at 0000000000000074
IP: neigh_timer_handler+0x1b1/0x3e0 net/core/neighbour.c:943
PGD 216785067 P4D 216785067 PUD 213633067 PMD 0 
Oops: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
kauditd_printk_skb: 409 callbacks suppressed
audit: type=1400 audit(1513519911.108:867): avc:  denied  { connect } for  pid=6367 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1
Modules linked in:
CPU: 1 PID: 3118 Comm: syz-fuzzer Not tainted 4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:neigh_timer_handler+0x1b1/0x3e0 net/core/neighbour.c:943
RSP: 0000:ffff88021fd03e08 EFLAGS: 00010206
RAX: ffff8802134c6440 RBX: ffff8802156c14c0 RCX: ffffffff820e5fca
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff8802156c1428
RBP: ffff88021fd03e48 R08: 0000000000000000 R09: ffffffff820e5e4d
R10: ffff88021fd03d78 R11: 0000000000000000 R12: ffff8802156c1400
R13: 0000000000000000 R14: ffff8802156c1428 R15: 0000000000000000
FS:  00007f9b787a7700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000074 CR3: 00000002135c1004 CR4: 00000000001626e0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x9f/0x3f0 kernel/time/timer.c:1320
 expire_timers kernel/time/timer.c:1357 [inline]
 __run_timers kernel/time/timer.c:1660 [inline]
 run_timer_softirq+0x68a/0x830 kernel/time/timer.c:1686
 __do_softirq+0xcb/0x4f3 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0xd4/0xe0 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:540 [inline]
 smp_apic_timer_interrupt+0x8e/0x2a0 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:920
 </IRQ>
RIP: 0033:0x40cd5d
RSP: 002b:000000c444a695a8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff11
RAX: 000000c44523de00 RBX: 000000002902f408 RCX: 0000000000000000
RDX: 000000c44523de00 RSI: 000000000000ffff RDI: 0000000000000000
RBP: 000000c444a695c0 R08: 000000000000000b R09: 000000c42001a228
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000000fb R14: 00000000000000fb R15: 000000000000000e
Code: 00 00 00 4c 89 e7 e8 ff e5 ff ff e9 81 00 00 00 e8 85 43 1d ff 41 f6 c5 08 0f 84 a6 00 00 00 e8 76 43 1d ff 4c 8b ab 58 ff ff ff <49> 63 57 74 4c 89 e8 48 2b 45 d0 48 01 c2 0f 88 7d 01 00 00 e8 
RIP: neigh_timer_handler+0x1b1/0x3e0 net/core/neighbour.c:943 RSP: ffff88021fd03e08
CR2: 0000000000000074
---[ end trace 00fcb0d447b2643c ]---