BUG: unable to handle kernel NULL pointer dereference at           (null)
IP:           (null)
PGD 1fa150067 P4D 1fa150067 PUD 1fd3f9067 PMD 0 
Oops: 0010 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 7646 Comm: syz-executor6 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:          (null)
RSP: 0018:ffff88021fd03748 EFLAGS: 00010206
RAX: ffff8801f8292580 RBX: ffff8801f8478d00 RCX: ffffffff8167e521
RDX: 0000000000000020 RSI: ffff8801fa34eea8 RDI: ffff8801f8478d00
RBP: ffff88021fd03788 R08: ffff88021fd0379f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801fa34eea8
R13: 0000000000000020 R14: ffff8801fa34ee00 R15: ffff8801fa22d850
FS:  00007f80bac0d700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001fa349006 CR4: 00000000001626e0
Call Trace:
 <IRQ>
 sctp_pack_cookie net/sctp/sm_make_chunk.c:1680 [inline]
 sctp_make_init_ack+0x24e/0x720 net/sctp/sm_make_chunk.c:418
 sctp_sf_do_5_1B_init+0x35a/0x450 net/sctp/sm_statefuns.c:426
 sctp_do_sm+0x80/0x1dc0 net/sctp/sm_sideeffect.c:1190
 sctp_endpoint_bh_rcv+0x142/0x2a0 net/sctp/endpointola.c:456
 sctp_inq_push+0x6a/0xb0 net/sctp/inqueue.c:95
 sctp_rcv+0xfa7/0x1180 net/sctp/input.c:267
 sctp6_rcv+0x15/0x30 net/sctp/ipv6.c:1006
 ip6_input_finish+0x149/0x890 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:281 [inline]
 ip6_input+0x41/0x220 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish+0x91/0x290 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:281 [inline]
 ipv6_rcv+0x5ba/0xb90 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x8a3/0x10c0 net/core/dev.c:4480
 __netif_receive_skb+0x2a/0x90 net/core/dev.c:4545
 process_backlog+0x113/0x310 net/core/dev.c:5224
 napi_poll net/core/dev.c:5622 [inline]
 net_rx_action+0x1a4/0x5f0 net/core/dev.c:5688
 __do_softirq+0xcb/0x4f3 kernel/softirq.c:285
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1133
 </IRQ>
 do_softirq.part.21+0x96/0xb0 kernel/softirq.c:329
 do_softirq kernel/softirq.c:177 [inline]
 __local_bh_enable_ip+0xf4/0x100 kernel/softirq.c:182
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:726 [inline]
 ip6_finish_output2+0x360/0xba0 net/ipv6/ip6_output.c:121
 ip6_finish_output+0x103/0x310 net/ipv6/ip6_output.c:146
 NF_HOOK_COND include/linux/netfilter.h:270 [inline]
 ip6_output+0x85/0x350 net/ipv6/ip6_output.c:163
 dst_output include/net/dst.h:443 [inline]
 NF_HOOK include/linux/netfilter.h:281 [inline]
 ip6_xmit+0x345/0x900 net/ipv6/ip6_output.c:261
 sctp_v6_xmit+0x14b/0x260 net/sctp/ipv6.c:225
 sctp_packet_transmit+0x988/0xd90 net/sctp/output.c:638
 sctp_outq_flush+0x2e3/0x1040 net/sctp/outqueue.c:913
 sctp_outq_uncork+0x33/0x40 net/sctp/outqueue.c:778
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1825 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1222 [inline]
 sctp_do_sm+0x1df/0x1dc0 net/sctp/sm_sideeffect.c:1193
 sctp_primitive_ASSOCIATE+0x57/0x70 net/sctp/primitive.c:88
 sctp_sendmsg+0x630/0x14d0 net/sctp/socket.c:2018
 inet_sendmsg+0x54/0x250 net/ipv4/af_inet.c:763
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0x51/0x70 net/socket.c:646
 SYSC_sendto+0x17f/0x1d0 net/socket.c:1727
 SyS_sendto+0x40/0x50 net/socket.c:1695
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a09
RSP: 002b:00007f80bac0cc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452a09
RDX: 0000000000000001 RSI: 0000000020937000 RDI: 0000000000000014
RBP: 0000000000000562 R08: 0000000020b62fe4 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f51d0
R13: 00000000ffffffff R14: 00007f80bac0d6d4 R15: 0000000000000000
Code:  Bad RIP value.
RIP:           (null) RSP: ffff88021fd03748
CR2: 0000000000000000
---[ end trace cbd14f035f77e700 ]---