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 (10605) >= skb_headlen() (10605) WARNING: CPU: 1 PID: 4587 at net/core/dev.c:3305 skb_checksum_help+0x626/0x740 net/core/dev.c:3304 Modules linked in: CPU: 1 PID: 4587 Comm: syz.2.252 Not tainted 6.1.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:skb_checksum_help+0x626/0x740 net/core/dev.c:3304 Code: ff df 48 8b 4c 24 18 0f b6 04 01 84 c0 0f 85 cd 00 00 00 48 8b 04 24 2b 18 48 c7 c7 80 cd 05 8c 44 89 fe 89 da e8 0a 77 b8 f8 <0f> 0b bb ea ff ff ff e9 59 fd ff ff e8 69 81 f0 f8 c6 05 0e 53 eb RSP: 0018:ffffc900170eef28 EFLAGS: 00010246 RAX: f9c712d9a2426100 RBX: 000000000000296d RCX: 0000000000040000 RDX: ffffc90005429000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 000000000000296d R08: ffffffff815293ae R09: fffff52002e1dd45 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000002a55 R13: ffff88802846b2f0 R14: ffff88802846b280 R15: 000000000000296d FS: 00007f4070dd66c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000e000 CR3: 00000000769e1000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774 iptunnel_xmit+0x513/0x920 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x22e4/0x2cc0 net/ipv4/ip_tunnel.c:840 __gre_xmit net/ipv4/ip_gre.c:474 [inline] ipgre_xmit+0x866/0xc40 net/ipv4/ip_gre.c:669 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293 packet_snd net/packet/af_packet.c:3076 [inline] packet_sendmsg+0x4775/0x61a0 net/packet/af_packet.c:3107 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514 ___sys_sendmsg net/socket.c:2568 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2597 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f406ff77299 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:00007f4070dd6048 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4070105f80 RCX: 00007f406ff77299 RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000008 RBP: 00007f406ffe48e6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f4070105f80 R15: 00007fffbabb9008