skb linear:   000000d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear:   000000e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear:   000000f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear:   00000100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear:   00000110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear:   00000120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
------------[ cut here ]------------
offset (10633) >= skb_headlen() (10633)
WARNING: CPU: 0 PID: 10883 at net/core/dev.c:3305 skb_checksum_help+0x626/0x740 net/core/dev.c:3304
Modules linked in:
CPU: 0 PID: 10883 Comm: syz.4.1487 Not tainted 6.1.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:skb_checksum_help+0x626/0x740 net/core/dev.c:3304
Code: ff df 48 8b 4c 24 18 0f b6 04 01 84 c0 0f 85 cd 00 00 00 48 8b 04 24 2b 18 48 c7 c7 a0 1b e1 8b 44 89 fe 89 da e8 da 2b d2 f8 <0f> 0b bb ea ff ff ff e9 59 fd ff ff e8 b9 2e 0a f9 c6 05 bf 25 df
RSP: 0018:ffffc90004826f28 EFLAGS: 00010246
RAX: ef412806af819c00 RBX: 0000000000002989 RCX: 0000000000040000
RDX: ffffc9000b424000 RSI: 00000000000130a8 RDI: 00000000000130a9
RBP: 0000000000002989 R08: ffffffff8152936e R09: fffffbfff1a23e21
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000002a31
R13: ffff888056e23e30 R14: ffff888056e23dc0 R15: 0000000000002989
FS:  00007f73db3a26c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000e000 CR3: 000000006a956000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774
 iptunnel_xmit+0x513/0x920 net/ipv4/ip_tunnel_core.c:82
 ip_tunnel_xmit+0x22e4/0x2cc0 net/ipv4/ip_tunnel.c:840
 __gre_xmit net/ipv4/ip_gre.c:474 [inline]
 ipgre_xmit+0x866/0xc40 net/ipv4/ip_gre.c:669
 __netdev_start_xmit include/linux/netdevice.h:4853 [inline]
 netdev_start_xmit include/linux/netdevice.h:4867 [inline]
 xmit_one net/core/dev.c:3627 [inline]
 dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643
 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293
 packet_snd net/packet/af_packet.c:3076 [inline]
 packet_sendmsg+0x4775/0x61a0 net/packet/af_packet.c:3107
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2597
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f73da575b99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f73db3a2048 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f73da704078 RCX: 00007f73da575b99
RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000006
RBP: 00007f73da5f677e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f73da704078 R15: 00007ffeb52a0808
 </TASK>