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+2 (4191) > skb_headlen() (1116) WARNING: CPU: 0 PID: 14706 at net/core/dev.c:3301 skb_checksum_help+0x5dc/0x730 net/core/dev.c:3301 Modules linked in: CPU: 0 PID: 14706 Comm: syz-executor.2 Not tainted 6.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 RIP: 0010:skb_checksum_help+0x5dc/0x730 net/core/dev.c:3301 Code: 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 4f 01 00 00 44 89 e2 2b 53 74 4c 89 ee 48 c7 c7 40 46 e9 8b e8 c4 ba d8 f8 <0f> 0b e9 8f fe ff ff e8 98 5d 69 f9 e9 53 fa ff ff 48 89 ef e8 cb RSP: 0018:ffffc90004347330 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88807c7f58c0 RCX: ffffc90009e29000 RDX: 0000000000040000 RSI: ffffffff814d2b16 RDI: 0000000000000001 RBP: ffff88807c7f5934 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 000000000000045c R13: 000000000000105f R14: ffff88807c7f5930 R15: 000000000000105d FS: 00007f71f1bcd6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000f000 CR3: 000000001f765000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip_do_fragment+0xa1b/0x18b0 net/ipv4/ip_output.c:777 ip_fragment.constprop.0+0x161/0x230 net/ipv4/ip_output.c:584 ip_finish_output_gso net/ipv4/ip_output.c:286 [inline] __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x49a/0x640 net/ipv4/ip_output.c:295 ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:323 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip_output+0x13b/0x290 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x190 net/ipv4/ip_output.c:129 iptunnel_xmit+0x618/0x9b0 net/ipv4/ip_tunnel_core.c:82 ipip6_tunnel_xmit net/ipv6/sit.c:1034 [inline] sit_tunnel_xmit+0xed2/0x28f0 net/ipv6/sit.c:1076 __netdev_start_xmit include/linux/netdevice.h:4918 [inline] netdev_start_xmit include/linux/netdevice.h:4932 [inline] xmit_one net/core/dev.c:3543 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3559 __dev_queue_xmit+0x9b4/0x3d10 net/core/dev.c:4344 dev_queue_xmit include/linux/netdevice.h:3112 [inline] packet_xmit+0x257/0x380 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x24d9/0x5580 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2190 __do_sys_sendto net/socket.c:2202 [inline] __se_sys_sendto net/socket.c:2198 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2198 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f71f0e7cae9 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:00007f71f1bcd0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f71f0f9bf80 RCX: 00007f71f0e7cae9 RDX: 000000000000fc13 RSI: 0000000020000280 RDI: 0000000000000004 RBP: 00007f71f0ec847a R08: 0000000000000000 R09: 000000000000002f R10: 0000000000000800 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f71f0f9bf80 R15: 00007ffdad76daf8