------------[ cut here ]------------
WARNING: CPU: 0 PID: 5003 at net/core/dev.c:3268 skb_checksum_help+0x4a3/0x5c0 net/core/dev.c:3268
Modules linked in:
CPU: 0 PID: 5003 Comm: syz-executor420 Not tainted 6.4.0-rc4-syzkaller-00275-g6c0ec7ab5aaf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:skb_checksum_help+0x4a3/0x5c0 net/core/dev.c:3268
Code: b2 76 f9 0f 0b 0f b6 1d d3 3c 57 06 31 ff 89 de e8 a2 ae 76 f9 84 db 0f 84 cf 00 00 00 41 bc ea ff ff ff eb ad e8 ad b2 76 f9 <0f> 0b 0f b6 1d ab 3c 57 06 31 ff 89 de e8 7b ae 76 f9 84 db 75 dd
RSP: 0018:ffffc90003a7f120 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 00000000000006a8 RCX: 0000000000000000
RDX: ffff88807d875940 RSI: ffffffff880d93a3 RDI: 0000000000000006
RBP: ffff8880727ca8c0 R08: 0000000000000006 R09: 00000000000006aa
R10: 0000000000000688 R11: ffffffff8a0ffe59 R12: ffff8880727ca934
R13: 00000000000006a8 R14: 0000000000000688 R15: 00000000000006aa
FS:  0000555556db7300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 0000000072896000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ip_do_fragment+0x99f/0x17d0 net/ipv4/ip_output.c:775
 ip_fragment.constprop.0+0x16b/0x240 net/ipv4/ip_output.c:582
 ip_finish_output_gso net/ipv4/ip_output.c:280 [inline]
 __ip_finish_output net/ipv4/ip_output.c:302 [inline]
 __ip_finish_output+0x4a0/0x650 net/ipv4/ip_output.c:289
 ip_finish_output+0x31/0x280 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:292 [inline]
 ip_output+0x1a3/0x320 net/ipv4/ip_output.c:431
 dst_output include/net/dst.h:458 [inline]
 ip_local_out+0xb3/0x1a0 net/ipv4/ip_output.c:126
 iptunnel_xmit+0x622/0xa40 net/ipv4/ip_tunnel_core.c:82
 ip_tunnel_xmit+0xfc0/0x3170 net/ipv4/ip_tunnel.c:831
 ipgre_xmit+0x6d3/0x8f0 net/ipv4/ip_gre.c:661
 __netdev_start_xmit include/linux/netdevice.h:4918 [inline]
 netdev_start_xmit include/linux/netdevice.h:4932 [inline]
 xmit_one net/core/dev.c:3578 [inline]
 dev_hard_start_xmit+0x187/0x700 net/core/dev.c:3594
 __dev_queue_xmit+0x2be2/0x3b10 net/core/dev.c:4244
 dev_queue_xmit include/linux/netdevice.h:3088 [inline]
 packet_xmit+0x260/0x390 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3081 [inline]
 packet_sendmsg+0x347f/0x5030 net/packet/af_packet.c:3113
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:747
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2503
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2557
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2586
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f8dcd27e559
Code: 28 c3 e8 4a 15 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe2cd72118 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffe2cd72128 RCX: 00007f8dcd27e559
RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 00007ffe2cd72130
R13: 00007ffe2cd72150 R14: 0000000000000000 R15: 0000000000000000
 </TASK>