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+2 (24217) > skb_headlen() (10637) WARNING: CPU: 1 PID: 23623 at net/core/dev.c:3334 skb_checksum_help+0x68f/0x730 net/core/dev.c:3333 Modules linked in: CPU: 1 PID: 23623 Comm: syz.4.6393 Not tainted 6.10.0-rc7-syzkaller-00254-g528dd46d0fc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:skb_checksum_help+0x68f/0x730 net/core/dev.c:3333 Code: 48 8b 4c 24 10 0f b6 04 01 84 c0 0f 85 89 00 00 00 48 8b 44 24 08 2b 18 48 c7 c7 c0 ac c5 8c 4c 89 f6 89 da e8 f2 c7 00 f8 90 <0f> 0b 90 90 bb ea ff ff ff e9 cf fc ff ff 48 8b 0c 24 80 e1 07 80 RSP: 0018:ffffc90008dbeda8 EFLAGS: 00010246 RAX: 09143f07be7fcf00 RBX: 000000000000298d RCX: 0000000000040000 RDX: ffffc9000ed14000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: dffffc0000000000 R08: ffffffff81585882 R09: fffffbfff1c39994 R10: dffffc0000000000 R11: fffffbfff1c39994 R12: 1ffff110045d1126 R13: 0000000000005e97 R14: 0000000000005e99 R15: ffff888022e888c0 FS: 00007f7d94a826c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000e000 CR3: 000000007b164000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip_do_fragment+0x21b/0x1b60 net/ipv4/ip_output.c:777 ip_finish_output_gso net/ipv4/ip_output.c:286 [inline] __ip_finish_output+0x290/0x400 net/ipv4/ip_output.c:308 iptunnel_xmit+0x540/0x9b0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x2113/0x2940 net/ipv4/ip_tunnel.c:857 __gre_xmit net/ipv4/ip_gre.c:483 [inline] ipgre_xmit+0x956/0xd40 net/ipv4/ip_gre.c:687 __netdev_start_xmit include/linux/netdevice.h:4882 [inline] netdev_start_xmit include/linux/netdevice.h:4896 [inline] xmit_one net/core/dev.c:3578 [inline] dev_hard_start_xmit+0x27a/0x7e0 net/core/dev.c:3594 __dev_queue_xmit+0x1b0e/0x3d30 net/core/dev.c:4393 packet_snd net/packet/af_packet.c:3080 [inline] packet_sendmsg+0x46c2/0x6150 net/packet/af_packet.c:3112 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7d93d75bd9 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:00007f7d94a82048 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7d93f03f60 RCX: 00007f7d93d75bd9 RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000003 RBP: 00007f7d93de4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7d93f03f60 R15: 00007ffef58bcac8