==================================================================
BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in erspan_rcv net/ipv4/ip_gre.c:284 [inline]
BUG: KMSAN: uninit-value in gre_rcv+0x11a8/0x1920 net/ipv4/ip_gre.c:424
CPU: 1 PID: 19706 Comm: syz-executor1 Not tainted 5.0.0-rc1+ #9
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+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
 __fswab32 include/uapi/linux/swab.h:59 [inline]
 erspan_rcv net/ipv4/ip_gre.c:284 [inline]
 gre_rcv+0x11a8/0x1920 net/ipv4/ip_gre.c:424
 gre_rcv+0x2dd/0x3c0 net/ipv4/gre_demux.c:143
 ip_protocol_deliver_rcu+0x584/0xba0 net/ipv4/ip_input.c:208
 ip_local_deliver_finish net/ipv4/ip_input.c:234 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip_local_deliver+0x624/0x7b0 net/ipv4/ip_input.c:255
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:414 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip_rcv+0x6b6/0x740 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core net/core/dev.c:4973 [inline]
 __netif_receive_skb net/core/dev.c:5083 [inline]
 process_backlog+0x756/0x10e0 net/core/dev.c:5923
 napi_poll net/core/dev.c:6346 [inline]
 net_rx_action+0x78b/0x1a60 net/core/dev.c:6412
 __do_softirq+0x53f/0x93a kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1039
 </IRQ>
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x16f/0x1a0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline]
 ip_finish_output2+0x1627/0x1820 net/ipv4/ip_output.c:231
 ip_finish_output+0xd2b/0xfd0 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_mc_output+0x117a/0x1700 net/ipv4/ip_output.c:390
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 raw_send_hdrinc net/ipv4/raw.c:432 [inline]
 raw_sendmsg+0x4182/0x4610 net/ipv4/raw.c:663
 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457e39
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f3ddc5dbc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457e39
RDX: 0000000000000028 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000120
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3ddc5dc6d4
R13: 00000000004c547e R14: 00000000004d9248 R15: 00000000ffffffff

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:220 [inline]
 kmsan_internal_chain_origin+0x134/0x230 mm/kmsan/kmsan.c:426
 kmsan_memcpy_memmove_metadata+0xcf2/0xf10 mm/kmsan/kmsan.c:304
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:324
 __msan_memcpy+0x58/0x70 mm/kmsan/kmsan_instr.c:139
 pskb_expand_head+0x34c/0x18f0 net/core/skbuff.c:1474
 __skb_cow include/linux/skbuff.h:2973 [inline]
 skb_cow_head include/linux/skbuff.h:3007 [inline]
 ip_tunnel_xmit+0x32e4/0x3980 net/ipv4/ip_tunnel.c:771
 __gre_xmit net/ipv4/ip_gre.c:453 [inline]
 erspan_xmit+0x2798/0x3890 net/ipv4/ip_gre.c:757
 __netdev_start_xmit include/linux/netdevice.h:4382 [inline]
 netdev_start_xmit include/linux/netdevice.h:4391 [inline]
 xmit_one net/core/dev.c:3278 [inline]
 dev_hard_start_xmit+0x604/0xc40 net/core/dev.c:3294
 sch_direct_xmit+0x58a/0x880 net/sched/sch_generic.c:327
 qdisc_restart net/sched/sch_generic.c:390 [inline]
 __qdisc_run+0x1cb7/0x34d0 net/sched/sch_generic.c:398
 qdisc_run include/net/pkt_sched.h:121 [inline]
 __dev_xmit_skb net/core/dev.c:3473 [inline]
 __dev_queue_xmit+0x215c/0x3b80 net/core/dev.c:3832
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3897
 neigh_resolve_output+0xab7/0xb40 net/core/neighbour.c:1471
 neigh_output include/net/neighbour.h:508 [inline]
 ip_finish_output2+0x1611/0x1820 net/ipv4/ip_output.c:229
 ip_finish_output+0xd2b/0xfd0 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_mc_output+0x117a/0x1700 net/ipv4/ip_output.c:390
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 raw_send_hdrinc net/ipv4/raw.c:432 [inline]
 raw_sendmsg+0x4182/0x4610 net/ipv4/raw.c:663
 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2754 [inline]
 __kmalloc_node_track_caller+0xe9e/0xff0 mm/slub.c:4377
 __kmalloc_reserve net/core/skbuff.c:140 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1012 [inline]
 alloc_skb_with_frags+0x1c7/0xac0 net/core/skbuff.c:5288
 sock_alloc_send_pskb+0xafd/0x10a0 net/core/sock.c:2091
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2108
 raw_send_hdrinc net/ipv4/raw.c:374 [inline]
 raw_sendmsg+0x25f5/0x4610 net/ipv4/raw.c:663
 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================