do_dccp_setsockopt: sockopt(PACKET_SIZE) is deprecated: fix your app
netlink: 2 bytes leftover after parsing attributes in process `syz-executor2'.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 1 PID: 19947 Comm: syz-executor2 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:
 __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_flush_dev+0x1b1/0x330 net/core/neighbour.c:253
 neigh_changeaddr+0x2f/0x40 net/core/neighbour.c:285
 arp_netdev_event+0x73/0x90 net/ipv4/arp.c:1252
 notifier_call_chain+0x41/0xc0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x32/0x60 net/core/dev.c:1679
 __dev_notify_flags+0x12a/0x130 net/core/dev.c:6888
 dev_change_flags+0x5e/0x70 net/core/dev.c:6910
 do_setlink+0x391/0x1570 net/core/rtnetlink.c:2256
 rtnl_setlink+0x12f/0x190 net/core/rtnetlink.c:2527
 rtnetlink_rcv_msg+0x333/0x5d0 net/core/rtnetlink.c:4522
 netlink_rcv_skb+0x92/0x160 net/netlink/af_netlink.c:2441
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4540
 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
 netlink_unicast+0x1d4/0x290 net/netlink/af_netlink.c:1334
 netlink_sendmsg+0x345/0x470 net/netlink/af_netlink.c:1897
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0x51/0x70 net/socket.c:646
 sock_write_iter+0xa4/0x100 net/socket.c:915
 call_write_iter include/linux/fs.h:1776 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x15b/0x1e0 fs/read_write.c:482
 vfs_write+0xf0/0x230 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0x57/0xd0 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007fcf2b268c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000026 RSI: 0000000020f1afda RDI: 0000000000000013
RBP: 0000000000000487 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4d48
R13: 00000000ffffffff R14: 00007fcf2b2696d4 R15: 0000000000000000
BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
IP: neigh_cleanup_and_release+0x13/0x70 net/core/neighbour.c:100
PGD 1dcd26067 P4D 1dcd26067 PUD 20cfce067 PMD 0 
Oops: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 19947 Comm: syz-executor2 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_cleanup_and_release+0x13/0x70 net/core/neighbour.c:100
RSP: 0018:ffffc90000fef6d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff880215307c00 RCX: ffffffff820e511f
RDX: 0000000000010000 RSI: ffffc90003815000 RDI: ffff880215307c00
RBP: ffffc90000fef6e8 R08: 0000000000000000 R09: ffffffff820e5421
R10: ffffc90000fef668 R11: 0000000000000000 R12: ffff88020ec6c5d8
R13: ffff8801e053b000 R14: ffff8801e053b000 R15: ffffffff831705f0
FS:  00007fcf2b269700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 00000001e3f71000 CR4: 00000000001426e0
Call Trace:
 neigh_flush_dev+0x270/0x330 net/core/neighbour.c:277
 neigh_changeaddr+0x2f/0x40 net/core/neighbour.c:285
 arp_netdev_event+0x73/0x90 net/ipv4/arp.c:1252
 notifier_call_chain+0x41/0xc0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x32/0x60 net/core/dev.c:1679
 __dev_notify_flags+0x12a/0x130 net/core/dev.c:6888
 dev_change_flags+0x5e/0x70 net/core/dev.c:6910
 do_setlink+0x391/0x1570 net/core/rtnetlink.c:2256
 rtnl_setlink+0x12f/0x190 net/core/rtnetlink.c:2527
 rtnetlink_rcv_msg+0x333/0x5d0 net/core/rtnetlink.c:4522
 netlink_rcv_skb+0x92/0x160 net/netlink/af_netlink.c:2441
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4540
 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
 netlink_unicast+0x1d4/0x290 net/netlink/af_netlink.c:1334
 netlink_sendmsg+0x345/0x470 net/netlink/af_netlink.c:1897
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0x51/0x70 net/socket.c:646
 sock_write_iter+0xa4/0x100 net/socket.c:915
 call_write_iter include/linux/fs.h:1776 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x15b/0x1e0 fs/read_write.c:482
 vfs_write+0xf0/0x230 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0x57/0xd0 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007fcf2b268c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000026 RSI: 0000000020f1afda RDI: 0000000000000013
RBP: 0000000000000487 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4d48
R13: 00000000ffffffff R14: 00007fcf2b2696d4 R15: 0000000000000000
Code: 1e 00 00 00 e8 af f4 ff ff 5b 5d c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 53 48 89 fb e8 21 52 1d ff 48 8b 43 10 <4c> 8b 60 28 4d 85 e4 74 0b e8 0f 52 1d ff 48 89 df 41 ff d4 e8 
RIP: neigh_cleanup_and_release+0x13/0x70 net/core/neighbour.c:100 RSP: ffffc90000fef6d8
CR2: 0000000000000028
---[ end trace e73cc2994beb1f41 ]---