==================================================================
BUG: KMSAN: uninit-value in ip_rcv+0xa93/0x16a0 net/ipv4/ip_input.c:464
CPU: 0 PID: 24707 Comm: syz-executor7 Not tainted 4.17.0+ #19
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:1465
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:651
 ip_rcv+0xa93/0x16a0 net/ipv4/ip_input.c:464
 __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]
 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+0x803/0x8f0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x4eb1/0x6610 net/ipv4/tcp.c:1410
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 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_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmmsg+0x490/0x850 net/socket.c:2212
 __do_sys_sendmmsg net/socket.c:2241 [inline]
 __se_sys_sendmmsg net/socket.c:2238 [inline]
 __x64_sys_sendmmsg+0x11c/0x170 net/socket.c:2238
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ab9
RSP: 002b:00007fe3d671ac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fe3d671b6d4 RCX: 0000000000455ab9
RDX: 0000000000000001 RSI: 0000000020002c80 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c0cee R14: 00000000004d0d70 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:312 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:327 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:717
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:494
 ip_send_check+0x11d/0x130 net/ipv4/ip_output.c:93
 inet_gso_segment+0x161a/0x1c10 net/ipv4/af_inet.c:1373
 inet_gso_segment+0x9d2/0x1c10 net/ipv4/af_inet.c:1339
 skb_mac_gso_segment+0x420/0x7b0 net/core/dev.c:2793
 __skb_gso_segment+0x757/0xa40 net/core/dev.c:2866
 skb_gso_segment include/linux/netdevice.h:4038 [inline]
 validate_xmit_skb+0xc30/0x1320 net/core/dev.c:3119
 __dev_queue_xmit+0x2370/0x3540 net/core/dev.c:3576
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3617
 neigh_hh_output include/net/neighbour.h:472 [inline]
 neigh_output include/net/neighbour.h:480 [inline]
 ip_finish_output2+0x12a8/0x1480 net/ipv4/ip_output.c:229
 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+0x164/0x1d0 net/ipv4/ip_output.c:124
 iptunnel_xmit+0x854/0xdb0 net/ipv4/ip_tunnel_core.c:91
 ip_tunnel_xmit+0x3422/0x37c0 net/ipv4/ip_tunnel.c:778
 sit_tunnel_xmit__ net/ipv6/sit.c:1013 [inline]
 sit_tunnel_xmit+0xd89/0x37e0 net/ipv6/sit.c:1026
 __netdev_start_xmit include/linux/netdevice.h:4087 [inline]
 netdev_start_xmit include/linux/netdevice.h:4096 [inline]
 xmit_one net/core/dev.c:3053 [inline]
 dev_hard_start_xmit+0x5f6/0xc80 net/core/dev.c:3069
 __dev_queue_xmit+0x2ad2/0x3540 net/core/dev.c:3584
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3617
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1398
 neigh_output include/net/neighbour.h:482 [inline]
 ip_finish_output2+0x1354/0x1480 net/ipv4/ip_output.c:229
 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+0x803/0x8f0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x4eb1/0x6610 net/ipv4/tcp.c:1410
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 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_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmmsg+0x490/0x850 net/socket.c:2212
 __do_sys_sendmmsg net/socket.c:2241 [inline]
 __se_sys_sendmmsg net/socket.c:2238 [inline]
 __x64_sys_sendmmsg+0x11c/0x170 net/socket.c:2238
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:312 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:327 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:717
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:494
 inet_gso_segment+0x1a38/0x1c10 net/ipv4/af_inet.c:1369
 inet_gso_segment+0x9d2/0x1c10 net/ipv4/af_inet.c:1339
 skb_mac_gso_segment+0x420/0x7b0 net/core/dev.c:2793
 __skb_gso_segment+0x757/0xa40 net/core/dev.c:2866
 skb_gso_segment include/linux/netdevice.h:4038 [inline]
 validate_xmit_skb+0xc30/0x1320 net/core/dev.c:3119
 __dev_queue_xmit+0x2370/0x3540 net/core/dev.c:3576
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3617
 neigh_hh_output include/net/neighbour.h:472 [inline]
 neigh_output include/net/neighbour.h:480 [inline]
 ip_finish_output2+0x12a8/0x1480 net/ipv4/ip_output.c:229
 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+0x164/0x1d0 net/ipv4/ip_output.c:124
 iptunnel_xmit+0x854/0xdb0 net/ipv4/ip_tunnel_core.c:91
 ip_tunnel_xmit+0x3422/0x37c0 net/ipv4/ip_tunnel.c:778
 sit_tunnel_xmit__ net/ipv6/sit.c:1013 [inline]
 sit_tunnel_xmit+0xd89/0x37e0 net/ipv6/sit.c:1026
 __netdev_start_xmit include/linux/netdevice.h:4087 [inline]
 netdev_start_xmit include/linux/netdevice.h:4096 [inline]
 xmit_one net/core/dev.c:3053 [inline]
 dev_hard_start_xmit+0x5f6/0xc80 net/core/dev.c:3069
 __dev_queue_xmit+0x2ad2/0x3540 net/core/dev.c:3584
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3617
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1398
 neigh_output include/net/neighbour.h:482 [inline]
 ip_finish_output2+0x1354/0x1480 net/ipv4/ip_output.c:229
 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+0x803/0x8f0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x4eb1/0x6610 net/ipv4/tcp.c:1410
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 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_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmmsg+0x490/0x850 net/socket.c:2212
 __do_sys_sendmmsg net/socket.c:2241 [inline]
 __se_sys_sendmmsg net/socket.c:2238 [inline]
 __x64_sys_sendmmsg+0x11c/0x170 net/socket.c:2238
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:312 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:327 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:717
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:560
 __msan_memcpy+0xda/0x130 mm/kmsan/kmsan_instr.c:443
 pskb_expand_head+0x3a6/0x1a70 net/core/skbuff.c:1470
 skb_header_unclone include/linux/skbuff.h:1470 [inline]
 iptunnel_handle_offloads+0x5ca/0x760 net/ipv4/ip_tunnel_core.c:171
 sit_tunnel_xmit__ net/ipv6/sit.c:1008 [inline]
 sit_tunnel_xmit+0x138/0x37e0 net/ipv6/sit.c:1026
 __netdev_start_xmit include/linux/netdevice.h:4087 [inline]
 netdev_start_xmit include/linux/netdevice.h:4096 [inline]
 xmit_one net/core/dev.c:3053 [inline]
 dev_hard_start_xmit+0x5f6/0xc80 net/core/dev.c:3069
 __dev_queue_xmit+0x2ad2/0x3540 net/core/dev.c:3584
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3617
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1398
 neigh_output include/net/neighbour.h:482 [inline]
 ip_finish_output2+0x1354/0x1480 net/ipv4/ip_output.c:229
 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+0x803/0x8f0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x4eb1/0x6610 net/ipv4/tcp.c:1410
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 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_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmmsg+0x490/0x850 net/socket.c:2212
 __do_sys_sendmmsg net/socket.c:2241 [inline]
 __se_sys_sendmmsg net/socket.c:2238 [inline]
 __x64_sys_sendmmsg+0x11c/0x170 net/socket.c:2238
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:312 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:222
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:348
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:355
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb_fclone include/linux/skbuff.h:1030 [inline]
 sk_stream_alloc_skb+0x17c/0xcf0 net/ipv4/tcp.c:875
 tcp_sendmsg_locked+0x237e/0x6610 net/ipv4/tcp.c:1290
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 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]
 sock_write_iter+0x3bc/0x470 net/socket.c:908
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x808/0x9f0 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1bf/0x3e0 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================