skbuff: skb_under_panic: text:ffffffff87faf860 len:48 put:8 head:ffff88801ddea800 data:ffff88801ddea7fc tail:0x2c end:0xc0 dev:sit1 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:120! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3623 Comm: syz-executor336 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:120 Code: f8 4c 8b 4c 24 10 8b 4b 70 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee 48 c7 c7 00 fb f4 8a ff 74 24 10 ff 74 24 20 e8 17 65 c1 ff <0f> 0b e8 3c 25 fd f7 4c 8b 64 24 18 e8 a2 c3 49 f8 48 c7 c1 60 08 RSP: 0018:ffffc900033deaf0 EFLAGS: 00010282 RAX: 0000000000000083 RBX: ffff88807067b6c0 RCX: 0000000000000000 RDX: ffff888078ec0140 RSI: ffffffff81605668 RDI: fffff5200067bd50 RBP: ffffffff8af50860 R08: 0000000000000083 R09: 0000000000000000 R10: 0000000000000400 R11: 66666666663a6b73 R12: ffffffff87faf860 R13: 0000000000000008 R14: ffff88802bd1c000 R15: 00000000000000c0 FS: 0000555555a9b300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200017c0 CR3: 000000007baee000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_under_panic net/core/skbuff.c:130 [inline] skb_push.cold+0x24/0x24 net/core/skbuff.c:2171 fou_build_udp+0x30/0x370 net/ipv4/fou.c:1054 gue_build_header+0xf7/0x140 net/ipv4/fou.c:1097 ip_tunnel_encap include/net/ip_tunnels.h:389 [inline] ip_tunnel_xmit+0x679/0x3170 net/ipv4/ip_tunnel.c:735 sit_tunnel_xmit__ net/ipv6/sit.c:1057 [inline] sit_tunnel_xmit+0x50f/0x2b70 net/ipv6/sit.c:1073 __netdev_start_xmit include/linux/netdevice.h:4840 [inline] netdev_start_xmit include/linux/netdevice.h:4854 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x183/0x880 net/core/dev.c:3606 __dev_queue_xmit+0x2c31/0x3ad0 net/core/dev.c:4256 dev_queue_xmit include/linux/netdevice.h:3008 [inline] neigh_connected_output+0x3c0/0x520 net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:546 [inline] ip_finish_output2+0x782/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x2d/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_mc_output+0x21b/0x700 net/ipv4/ip_output.c:415 dst_output include/net/dst.h:445 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0xd4/0x260 net/ipv4/ip_output.c:1586 udp_send_skb+0x725/0x1430 net/ipv4/udp.c:971 udp_sendmsg+0x1bb8/0x2740 net/ipv4/udp.c:1258 udpv6_sendmsg+0x17da/0x2c70 net/ipv6/udp.c:1378 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:653 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x334/0x8c0 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmmsg+0x18b/0x460 net/socket.c:2622 __do_sys_sendmmsg net/socket.c:2651 [inline] __se_sys_sendmmsg net/socket.c:2648 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2648 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0500994489 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd460367f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0500994489 RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000a01e40 R09: 0000000000a01e40 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000ab20 R13: 00007ffd46036820 R14: 00007ffd46036810 R15: 00007ffd46036804 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:120 Code: f8 4c 8b 4c 24 10 8b 4b 70 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee 48 c7 c7 00 fb f4 8a ff 74 24 10 ff 74 24 20 e8 17 65 c1 ff <0f> 0b e8 3c 25 fd f7 4c 8b 64 24 18 e8 a2 c3 49 f8 48 c7 c1 60 08 RSP: 0018:ffffc900033deaf0 EFLAGS: 00010282 RAX: 0000000000000083 RBX: ffff88807067b6c0 RCX: 0000000000000000 RDX: ffff888078ec0140 RSI: ffffffff81605668 RDI: fffff5200067bd50 RBP: ffffffff8af50860 R08: 0000000000000083 R09: 0000000000000000 R10: 0000000000000400 R11: 66666666663a6b73 R12: ffffffff87faf860 R13: 0000000000000008 R14: ffff88802bd1c000 R15: 00000000000000c0 FS: 0000555555a9b300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200017c0 CR3: 000000007baee000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400