------------[ cut here ]------------ WARNING: CPU: 1 PID: 5400 at net/core/dev.c:3268 skb_checksum_help+0x3d3/0x5b0 Modules linked in: CPU: 1 PID: 5400 Comm: syz-executor.0 Not tainted 6.4.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:skb_checksum_help+0x3d3/0x5b0 net/core/dev.c:3268 Code: 4c 89 ff e8 ff 01 00 00 bb ea ff ff ff eb cf 0f 0b 80 3d 11 26 a6 05 01 0f 85 a8 01 00 00 e8 14 57 ef f8 bb ea ff ff ff eb b4 <0f> 0b 80 3d f7 25 a6 05 01 0f 85 9b 01 00 00 e8 f9 56 ef f8 bb ea RSP: 0018:ffffc9000465ef08 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 00000000000006aa RCX: ffff88801dbfbb80 RDX: ffff88802b413bb4 RSI: 0000000000000688 RDI: 00000000000006aa RBP: 0000000000000688 R08: ffffffff889ade98 R09: ffffffff88956640 R10: ffffffff88956610 R11: ffffffff88956640 R12: 1ffff11005682778 R13: ffff88802b413bb0 R14: dffffc0000000000 R15: ffff88802b413b40 FS: 00007fe18e9f2700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001000 CR3: 0000000017436000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip_do_fragment+0x21a/0x1b00 net/ipv4/ip_output.c:775 ip_finish_output_gso net/ipv4/ip_output.c:280 [inline] __ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:302 iptunnel_xmit+0x532/0x9b0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x20bf/0x2920 net/ipv4/ip_tunnel.c:831 __gre_xmit net/ipv4/ip_gre.c:469 [inline] ipgre_xmit+0x757/0xa50 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+0x241/0x750 net/core/dev.c:3594 __dev_queue_xmit+0x193c/0x3750 net/core/dev.c:4244 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x4535/0x6040 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x58f/0x890 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmsg+0x2ad/0x390 net/socket.c:2586 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe18dc8c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 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:00007fe18e9f2168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe18ddabf80 RCX: 00007fe18dc8c169 RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000003 RBP: 00007fe18dce7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff0f1fc53f R14: 00007fe18e9f2300 R15: 0000000000022000