skb frag:     00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb frag:     00000010: 00 00 00 00 00 00 00 00 00 00 00 00
------------[ cut here ]------------
offset+2 (43049) > skb_headlen() (100)
WARNING: CPU: 0 PID: 5104 at net/core/dev.c:3334 skb_checksum_help+0x68f/0x730 net/core/dev.c:3333
Modules linked in:
CPU: 0 PID: 5104 Comm: syz-executor183 Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:skb_checksum_help+0x68f/0x730 net/core/dev.c:3333
Code: 48 8b 4c 24 10 0f b6 04 01 84 c0 0f 85 89 00 00 00 48 8b 44 24 08 2b 18 48 c7 c7 a0 4e c5 8c 4c 89 f6 89 da e8 02 1f ff f7 90 <0f> 0b 90 90 bb ea ff ff ff e9 cf fc ff ff 48 8b 0c 24 80 e1 07 80
RSP: 0018:ffffc9000312eda8 EFLAGS: 00010246
RAX: e5ff1285c7fc2800 RBX: 0000000000000064 RCX: ffff888029cf1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff815857d2 R09: fffffbfff1c3996c
R10: dffffc0000000000 R11: fffffbfff1c3996c R12: 1ffff110045bd40e
R13: 000000000000a827 R14: 000000000000a829 R15: ffff888022dea000
FS:  0000555581bd9380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000d000 CR3: 0000000021b40000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ip_do_fragment+0x21b/0x1b60 net/ipv4/ip_output.c:777
 ip_finish_output_gso net/ipv4/ip_output.c:286 [inline]
 __ip_finish_output+0x290/0x400 net/ipv4/ip_output.c:308
 iptunnel_xmit+0x540/0x9b0 net/ipv4/ip_tunnel_core.c:82
 ip_tunnel_xmit+0x2113/0x2940 net/ipv4/ip_tunnel.c:857
 __gre_xmit net/ipv4/ip_gre.c:483 [inline]
 ipgre_xmit+0x956/0xd40 net/ipv4/ip_gre.c:687
 __netdev_start_xmit include/linux/netdevice.h:4882 [inline]
 netdev_start_xmit include/linux/netdevice.h:4896 [inline]
 xmit_one net/core/dev.c:3578 [inline]
 dev_hard_start_xmit+0x27c/0x7e0 net/core/dev.c:3594
 __dev_queue_xmit+0x1b0e/0x3d30 net/core/dev.c:4393
 packet_snd net/packet/af_packet.c:3080 [inline]
 packet_sendmsg+0x46a9/0x6130 net/packet/af_packet.c:3112
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f079977eb69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc0fb017e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f079977eb69
RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000003
RBP: 00000000000f4240 R08: 0000000100000000 R09: 0000000100000000
R10: 0000000000000004 R11: 0000000000000246 R12: 00007ffc0fb01840
R13: 0000000000000001 R14: 00007ffc0fb01840 R15: 0000000000000003
 </TASK>