BUG: unable to handle kernel NULL pointer dereference at           (null)
IP:           (null)
PGD 1fac46067 P4D 1fac46067 PUD 1f9e06067 PMD 0 
Oops: 0010 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 9686 Comm: syz-executor7 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:ffff88021fd03778 EFLAGS: 00010206
RAX: ffff8801f9fc8240 RBX: ffff8801fbf13400 RCX: ffffffff8167e521
RDX: 0000000000000020 RSI: ffff8801f9af88a8 RDI: ffff8801fbf13400
RBP: ffff88021fd037b8 R08: ffff88021fd037cf R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801f9af88a8
R13: 0000000000000020 R14: ffff8801f9af8800 R15: ffff8801fbab8c50
FS:  00007fd28ec7e700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001f9ba6006 CR4: 00000000001606e0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
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
 ip_local_deliver_finish+0xe4/0x480 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:281 [inline]
 ip_local_deliver+0x7e/0x270 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:449 [inline]
 ip_rcv_finish+0x259/0x6d0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:281 [inline]
 ip_rcv+0x33c/0x620 net/ipv4/ip_input.c:493
 __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]
 ip_finish_output2+0x312/0x7b0 net/ipv4/ip_output.c:231
 ip_finish_output+0x2e6/0x490 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:270 [inline]
 ip_output+0x73/0x2b0 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:443 [inline]
 ip_local_out+0x54/0xb0 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x27d/0x740 net/ipv4/ip_output.c:504
 sctp_v4_xmit+0x48/0x50 net/sctp/protocol.c:994
 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_connect+0x3c1/0x4e0 net/sctp/socket.c:1254
 sctp_connect+0x5c/0x80 net/sctp/socket.c:4330
 inet_dgram_connect+0x78/0xb0 net/ipv4/af_inet.c:541
 SYSC_connect+0xaf/0x130 net/socket.c:1619
 SyS_connect+0x24/0x30 net/socket.c:1600
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a09
RSP: 002b:00007fd28ec7dc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007fd28ec7e700 RCX: 0000000000452a09
RDX: 0000000000000010 RSI: 0000000020867ff0 RDI: 0000000000000014
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ff R14: 00007fd28ec7e9c0 R15: 0000000000000000
Code:  Bad RIP value.
RIP:           (null) RSP: ffff88021fd03778
CR2: 0000000000000000
---[ end trace ce77918882706a78 ]---