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: 15766 at net/core/dev.c:3303 skb_checksum_help+0x5e2/0x740 net/core/dev.c:3303 Modules linked in: CPU: 0 PID: 15766 Comm: syz-executor.1 Not tainted 6.7.0-rc4-syzkaller-00039-g9ace34a8e446 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:skb_checksum_help+0x5e2/0x740 net/core/dev.c:3303 Code: 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 52 01 00 00 44 89 e2 2b 53 74 4c 89 ee 48 c7 c7 40 5f e9 8b e8 bf 34 dd f8 90 <0f> 0b 90 90 e9 87 fe ff ff e8 90 b4 6d f9 e9 4b fa ff ff 48 89 ef RSP: 0018:ffffc90014ee7318 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff8880207308c0 RCX: ffffc90009d09000 RDX: 0000000000040000 RSI: ffffffff814db216 RDI: 0000000000000001 RBP: ffff888020730934 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: fffffffffffd2e78 R12: 000000000000045c R13: 000000000000105f R14: ffff888020730930 R15: 000000000000105d FS: 0000000000000000(0000) GS:ffff8880b9800000(0063) knlGS:00000000f7f59b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000002000f000 CR3: 0000000053e02000 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+0x49c/0x650 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/0x2a0 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:129 iptunnel_xmit+0x5b4/0x9b0 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:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3545 [inline] dev_hard_start_xmit+0x13d/0x6d0 net/core/dev.c:3561 __dev_queue_xmit+0x7c1/0x3d60 net/core/dev.c:4346 dev_queue_xmit include/linux/netdevice.h:3134 [inline] packet_xmit+0x257/0x380 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x24ca/0x5240 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] __ia32_sys_sendto+0xdd/0x1b0 net/socket.c:2198 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a RIP: 0023:0xf7f5e579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7f595ac EFLAGS: 00000292 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000280 RDX: 000000000000fc13 RSI: 0000000000000800 RDI: 0000000000000000 RBP: 000000000000002f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi