syzbot

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BUG: KMSAN: uninit-value in skb_network_header include/linux/skbuff.h:2305 [inline]
BUG: KMSAN: uninit-value in ip_hdr include/linux/ip.h:25 [inline]
BUG: KMSAN: uninit-value in ipt_do_table+0x25f8/0x2750 net/ipv4/netfilter/ip_tables.c:247
CPU: 0 PID: 9285 Comm: syz-executor4 Not tainted 4.17.0+ #17
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:1368
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:634
 skb_network_header include/linux/skbuff.h:2305 [inline]
 ip_hdr include/linux/ip.h:25 [inline]
 ipt_do_table+0x25f8/0x2750 net/ipv4/netfilter/ip_tables.c:247
 iptable_raw_hook+0xb5/0xe0 net/ipv4/netfilter/iptable_raw.c:43
 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_rcv+0x10bf/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
IPVS: ftp: loaded support on port[0] = 21
 release_sock net/core/sock.c:2850 [inline]
 sk_wait_data+0x2ba/0x920 net/core/sock.c:2377
 tcp_recvmsg+0x1e69/0x40b0 net/ipv4/tcp.c:1920
 inet_recvmsg+0x4e3/0x610 net/ipv4/af_inet.c:830
 sock_recvmsg_nosec net/socket.c:802 [inline]
 sock_recvmsg net/socket.c:809 [inline]
 __sys_recvfrom+0x648/0x820 net/socket.c:1846
 __do_sys_recvfrom net/socket.c:1864 [inline]
 __se_sys_recvfrom net/socket.c:1860 [inline]
 __x64_sys_recvfrom+0x1a2/0x210 net/socket.c:1860
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ab9
RSP: 002b:00007fb6aaac9c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: ffffffffffffffda RBX: 00007fb6aaaca6d4 RCX: 0000000000455ab9
RDX: 6478c8501c739c9d RSI: 0000000020f9cf9b RDI: 0000000000000013
RBP: 000000000072bf48 R08: 0000000000000000 R09: 0000000000000035
R10: 00000000003e9538 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c09d7 R14: 00000000004d07b8 R15: 0000000000000001

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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