syzbot

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
 should_failslab+0xec/0x120 mm/failslab.c:32
Modules linked in:
 slab_pre_alloc_hook mm/slab.h:422 [inline]
 slab_alloc_node mm/slab.c:3286 [inline]
 kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3629
CPU: 1 PID: 7889 Comm: syz-executor0 Not tainted 4.15.0+ #221
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193
RIP: 0010:ip6t_do_table+0x132d/0x1a30 net/ipv6/netfilter/ip6_tables.c:355
RSP: 0018:ffff8801db506c20 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801ce5ecdc0 RCX: ffffffff84db22a1
 alloc_skb include/linux/skbuff.h:983 [inline]
 netlink_dump+0x545/0xcf0 net/netlink/af_netlink.c:2203
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8801ce5ecf1e
RBP: ffff8801db506e68 R08: ffff8801db506f60 R09: 0000000000000000
R10: 00000000000000d0 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8801ce5ece90
FS:  00007f0c49646700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020809000 CR3: 00000001ce42c001 CR4: 00000000001606e0
 __netlink_dump_start+0x4f0/0x6d0 net/netlink/af_netlink.c:2319
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 netlink_dump_start include/linux/netlink.h:214 [inline]
 rtnetlink_rcv_msg+0x7f0/0xb10 net/core/rtnetlink.c:4550
Call Trace:
 <IRQ>
 netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2442
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4605
 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
 netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
 ip6table_security_hook+0x65/0x80 net/ipv6/netfilter/ip6table_security.c:45
 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline]
 nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483
 nf_hook include/linux/netfilter.h:243 [inline]
 NF_HOOK include/linux/netfilter.h:286 [inline]
 ip6_input+0x35c/0x560 net/ipv6/ip6_input.c:327
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish+0x297/0x8c0 net/ipv6/ip6_input.c:71
 sock_write_iter+0x31a/0x5d0 net/socket.c:909
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0xf37/0x1fa0 net/ipv6/ip6_input.c:208
 call_write_iter include/linux/fs.h:1781 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:482
 __netif_receive_skb_core+0x1a41/0x3460 net/core/dev.c:4547
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x453299
RSP: 002b:00007f091c24dc58 EFLAGS: 00000212
 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f091c24daa0 RCX: 0000000000453299
RDX: 0000000000000024 RSI: 0000000020157ff9 RDI: 0000000000000013
RBP: 00007f091c24da90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b8096
R13: 00007f091c24dbc8 R14: 00000000004b8096 R15: 0000000000000000
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4612
 process_backlog+0x203/0x740 net/core/dev.c:5292
 napi_poll net/core/dev.c:5690 [inline]
 net_rx_action+0x792/0x1910 net/core/dev.c:5756
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1151
 </IRQ>
 do_softirq.part.19+0x14d/0x190 kernel/softirq.c:329
 do_softirq kernel/softirq.c:177 [inline]
 __local_bh_enable_ip+0x1ee/0x230 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+0xba0/0x23a0 net/ipv6/ip6_output.c:121
 ip6_finish_output+0x698/0xaf0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip6_output+0x1eb/0x840 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:443 [inline]
 ip6_local_out+0x95/0x160 net/ipv6/output_core.c:176
 ip6_send_skb+0xa1/0x330 net/ipv6/ip6_output.c:1677
 udp_v6_send_skb+0x5ee/0xf70 net/ipv6/udp.c:1044
 udpv6_sendmsg+0x2835/0x3400 net/ipv6/udp.c:1316
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 SYSC_sendto+0x361/0x5c0 net/socket.c:1747
 SyS_sendto+0x40/0x50 net/socket.c:1715
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x453299
RSP: 002b:00007f0c49645c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299
RDX: 00000000000007d0 RSI: 0000000020adb000 RDI: 0000000000000013
RBP: 00000000000005ca R08: 0000000020809000 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f7b90
R13: 00000000ffffffff R14: 00007f0c496466d4 R15: 0000000000000000
Code: 41 f6 87 83 00 00 00 04 75 37 e8 0f 83 95 fc 8b 85 14 fe ff ff 48 8b b5 50 fe ff ff 4c 8d 2c c6 44 8d 60 01 4c 89 e8 48 c1 e8 03 <42> 80 3c 30 00 0f 85 26 03 00 00 4d 89 7d 00 44 89 a5 14 fe ff 
RIP: ip6t_do_table+0x132d/0x1a30 net/ipv6/netfilter/ip6_tables.c:355 RSP: ffff8801db506c20
---[ end trace 688cdfa97922675e ]---