------------[ cut here ]------------ WARNING: CPU: 0 PID: 12929 at net/core/dev.c:3295 skb_checksum_help+0x3b8/0x5b0 Modules linked in: CPU: 0 PID: 12929 Comm: syz-executor.3 Not tainted 6.5.0-syzkaller-12883-g2a5a4326e583 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 RIP: 0010:skb_checksum_help+0x3b8/0x5b0 net/core/dev.c:3295 Code: 41 5c 41 5d 41 5e 41 5f 5d c3 e8 43 7a db f8 bb f4 ff ff ff eb e3 e8 37 7a db f8 4c 89 ff e8 bf fa ff ff bb ea ff ff ff eb cf <0f> 0b 80 3d bd 3e d3 05 01 0f 85 a8 01 00 00 e8 14 7a db f8 bb ea RSP: 0018:ffffc9000ab2eee8 EFLAGS: 00010212 RAX: 0000000000000002 RBX: 000000000000007c RCX: 0000000000040000 RDX: ffff88801eee0000 RSI: 000000000000007c RDI: 0000000000000519 RBP: 0000000000000519 R08: ffffffff88b227db R09: 0000000000000000 R10: ffffc9000ab2f080 R11: fffff52001565e14 R12: 1ffff11008d32f9e R13: ffff888046997cf0 R14: 0000000000000080 R15: ffff888046997c80 FS: 00007f398f0796c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001000 CR3: 0000000027933000 CR4: 00000000003506f0 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:284 [inline] __ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:306 iptunnel_xmit+0x538/0x9a0 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:662 __netdev_start_xmit include/linux/netdevice.h:4889 [inline] netdev_start_xmit include/linux/netdevice.h:4903 [inline] xmit_one net/core/dev.c:3544 [inline] dev_hard_start_xmit+0x241/0x750 net/core/dev.c:3560 __dev_queue_xmit+0x19e8/0x3a60 net/core/dev.c:4340 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x47e8/0x6230 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x592/0x890 net/socket.c:2541 ___sys_sendmsg net/socket.c:2595 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2624 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f398e27cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f398f0790c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f398e39bf80 RCX: 00007f398e27cae9 RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000003 RBP: 00007f398e2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f398e39bf80 R15: 00007ffe9119b968