syzbot

BUG: unable to handle kernel NULL pointer dereference at 0000000000000160
PGD 800000012785b067 P4D 800000012785b067 PUD 1a3097067 PMD 0 
Oops: 0000 [#1] SMP PTI
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 8300 Comm: syz-executor6 Not tainted 4.17.0+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ip6_rt_get_dev_rcu net/ipv6/route.c:1041 [inline]
RIP: 0010:ip6_rt_pcpu_alloc net/ipv6/route.c:1099 [inline]
RIP: 0010:rt6_make_pcpu_route net/ipv6/route.c:1128 [inline]
RIP: 0010:ip6_pol_route+0x4469/0x5d40 net/ipv6/route.c:1790
RSP: 0018:ffff88021fd0e640 EFLAGS: 00010246
RAX: ffffffff8b5fe000 RBX: 0000000000000160 RCX: 0000000000100000
RDX: ffffffff8b5ff000 RSI: 0000000000000000 RDI: ffffea0006000000
RBP: ffff88021fd0e7e8 R08: 0000000000000000 R09: ffff88021fd39050
R10: 0000000000000000 R11: ffffffff88b61ba0 R12: ffff88012f1d6000
R13: ffff8801000004e0 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fa21b072700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000160 CR3: 0000000121fac000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 ip6_pol_route_output+0x11b/0x140 net/ipv6/route.c:1969
 fib6_rule_lookup+0x323/0x7a0 net/ipv6/fib6_rules.c:85
 ip6_route_output_flags+0x504/0x5a0 net/ipv6/route.c:1997
 ip6_route_output include/net/ip6_route.h:88 [inline]
 ip6_dst_lookup_tail+0xd7b/0x1a50 net/ipv6/ip6_output.c:973
 ip6_dst_lookup_flow+0xfc/0x270 net/ipv6/ip6_output.c:1096
 sctp_v6_get_dst+0x6a6/0x1b90 net/sctp/ipv6.c:274
 sctp_transport_route+0x12f/0x650 net/sctp/transport.c:293
 sctp_assoc_add_peer+0x810/0x1e20 net/sctp/associola.c:655
 sctp_process_param net/sctp/sm_make_chunk.c:2573 [inline]
 sctp_process_init+0x18ce/0x3b60 net/sctp/sm_make_chunk.c:2389
 sctp_sf_do_5_1B_init+0xe10/0x1b50 net/sctp/sm_statefuns.c:416
 sctp_do_sm+0x2a2/0x9190 net/sctp/sm_sideeffect.c:1188
 sctp_endpoint_bh_rcv+0xd55/0x1040 net/sctp/endpointola.c:456
 sctp_inq_push+0x314/0x460 net/sctp/inqueue.c:95
 sctp_rcv+0x43db/0x4d30 net/sctp/input.c:267
IPv6: ADDRCONF(NETDEV_CHANGE): ifb0: link becomes ready
 sctp6_rcv+0x41/0x70 net/sctp/ipv6.c:1045
 ip6_input_finish+0x1353/0x2260 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x498/0x6e0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x1d6b/0x2360 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47f3/0x4aa0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x766/0x1a80 net/core/dev.c:5801
 __do_softirq+0x592/0x979 kernel/softirq.c:285
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1054
 </IRQ>
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x114/0x140 kernel/softirq.c:182
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:728 [inline]
 ip6_finish_output2+0x1ce8/0x2100 net/ipv6/ip6_output.c:121
 ip6_finish_output+0xaf0/0xbb0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip6_output+0x597/0x6c0 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_xmit+0x2067/0x2370 net/ipv6/ip6_output.c:277
 sctp_v6_xmit+0x48d/0x570 net/sctp/ipv6.c:225
 sctp_packet_transmit+0x3ecf/0x4370 net/sctp/output.c:650
 sctp_outq_flush+0x1044/0x6430 net/sctp/outqueue.c:911
 sctp_outq_uncork+0xd2/0xf0 net/sctp/outqueue.c:776
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1820 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline]
 sctp_do_sm+0x8b32/0x9190 net/sctp/sm_sideeffect.c:1191
 sctp_primitive_ASSOCIATE+0x172/0x1a0 net/sctp/primitive.c:88
 sctp_sendmsg_to_asoc+0x1816/0x2690 net/sctp/socket.c:1934
 sctp_sendmsg+0x3c41/0x5fc0 net/sctp/socket.c:2122
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 __sys_sendto+0x6c4/0x7e0 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0x1a1/0x210 net/socket.c:1797
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ba9
RSP: 002b:00007fa21b071c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fa21b0726d4 RCX: 0000000000455ba9
RDX: 0000000000000001 RSI: 0000000020847fff RDI: 0000000000000015
RBP: 000000000072bea0 R08: 000000002005ffe4 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c119c R14: 00000000004d1328 R15: 0000000000000000
Code: 00 48 83 7d c8 00 4c 8b 7d b0 0f 85 2d 0f 00 00 bb 60 01 00 00 49 03 5d 00 4c 89 ef e8 51 2d 08 f9 48 83 38 00 0f 85 1f 0f 00 00 <4c> 8b 2b 48 89 df e8 3c 2d 08 f9 48 8b 00 48 89 45 c8 8b 02 89 
RIP: ip6_rt_get_dev_rcu net/ipv6/route.c:1041 [inline] RSP: ffff88021fd0e640
RIP: ip6_rt_pcpu_alloc net/ipv6/route.c:1099 [inline] RSP: ffff88021fd0e640
RIP: rt6_make_pcpu_route net/ipv6/route.c:1128 [inline] RSP: ffff88021fd0e640
RIP: ip6_pol_route+0x4469/0x5d40 net/ipv6/route.c:1790 RSP: ffff88021fd0e640
CR2: 0000000000000160
---[ end trace e09fbdf17d23737d ]---