syzbot

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BUG: KMSAN: uninit-value in nf_ct_get include/net/netfilter/nf_conntrack.h:148 [inline]
BUG: KMSAN: uninit-value in nf_nat_ipv4_fn+0x20e/0xdd0 net/ipv4/netfilter/nf_nat_l3proto_ipv4.c:258
CPU: 0 PID: 9886 Comm: syz-executor6 Not tainted 4.17.0+ #16
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1352
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:634
 nf_ct_get include/net/netfilter/nf_conntrack.h:148 [inline]
 nf_nat_ipv4_fn+0x20e/0xdd0 net/ipv4/netfilter/nf_nat_l3proto_ipv4.c:258
 iptable_nat_ipv4_fn+0xa0/0xb0 net/ipv4/netfilter/iptable_nat.c:46
 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline]
 nf_hook_slow+0x15d/0x3e0 net/netfilter/core.c:483
 nf_hook include/linux/netfilter.h:243 [inline]
 NF_HOOK include/linux/netfilter.h:286 [inline]
 ip_local_deliver+0x399/0x4e0 net/ipv4/ip_input.c:256
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0xa1b/0x1d10 net/ipv4/ip_input.c:396
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x1168/0x16a0 net/ipv4/ip_input.c:492
 __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:1052
 </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]
 ip_finish_output2+0x136a/0x1480 net/ipv4/ip_output.c:231
 ip_finish_output+0xcbc/0x1000 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip_output+0x505/0x5d0 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out net/ipv4/ip_output.c:124 [inline]
 ip_queue_xmit+0x1b0f/0x1d00 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x3db5/0x5350 net/ipv4/tcp_output.c:1176
 tcp_write_xmit+0x2d81/0xb200 net/ipv4/tcp_output.c:2373
 __tcp_push_pending_frames+0x124/0x400 net/ipv4/tcp_output.c:2546
 tcp_push_pending_frames include/net/tcp.h:1681 [inline]
 tcp_data_snd_check+0x184/0xe60 net/ipv4/tcp_input.c:5012
 tcp_rcv_established+0x1980/0x2bb0 net/ipv4/tcp_input.c:5462
 tcp_v4_do_rcv+0x6d2/0xd90 net/ipv4/tcp_ipv4.c:1477
 sk_backlog_rcv include/net/sock.h:909 [inline]
 __release_sock+0x2dc/0x680 net/core/sock.c:2335
 release_sock+0x99/0x2a0 net/core/sock.c:2850
 tcp_sendmsg+0xd6/0x100 net/ipv4/tcp.c:1448
 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: 0033:0x455ab9
RSP: 002b:00007f579eeeec68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f579eeef6d4 RCX: 0000000000455ab9
RDX: fffffffffffffd43 RSI: 0000000020de1fff RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000020db4ff0 R09: 0000000000000010
R10: 0000000020008005 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c0f1a R14: 00000000004d0e40 R15: 0000000000000000

Local variable description: ----skb.addr@__netif_receive_skb_core
Variable was created at:
 __netif_receive_skb_core+0xb7/0x4aa0 net/core/dev.c:4462
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
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