skbuff: skb_under_panic: text:ffffffff87bd970f len:48 put:8 head:ffff888079b2a000 data:ffff888079b29ffc tail:0x2c end:0xc0 dev:sit2 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:113! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 31564 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:113 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 60 fc 8b 8a ff 74 24 10 ff 74 24 20 e8 86 65 c2 ff <0f> 0b e8 53 23 45 f8 4c 8b 64 24 18 e8 79 87 8b f8 48 c7 c1 00 09 RSP: 0018:ffffc90004cc6ad0 EFLAGS: 00010282 RAX: 0000000000000083 RBX: ffff88807f4333c0 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815ef908 RDI: fffff52000998d4c RBP: ffffffff8a8c0900 R08: 0000000000000083 R09: 0000000000000000 R10: ffffffff815e96ee R11: 0000000000000000 R12: ffffffff87bd970f R13: 0000000000000008 R14: ffff888028ec4000 R15: 00000000000000c0 FS: 00007f2e1eb5b700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31f23000 CR3: 0000000038832000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_under_panic net/core/skbuff.c:123 [inline] skb_push.cold+0x24/0x24 net/core/skbuff.c:2009 fou_build_udp+0x2f/0x350 net/ipv4/fou.c:1067 gue_build_header+0xf7/0x140 net/ipv4/fou.c:1110 ip_tunnel_encap include/net/ip_tunnels.h:370 [inline] ip_tunnel_xmit+0x5d3/0x2b60 net/ipv4/ip_tunnel.c:732 sit_tunnel_xmit__ net/ipv6/sit.c:1065 [inline] sit_tunnel_xmit+0x4fd/0x2aa0 net/ipv6/sit.c:1081 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606 __dev_queue_xmit+0x299a/0x3630 net/core/dev.c:4226 neigh_connected_output+0x3b6/0x510 net/core/neighbour.c:1552 neigh_output include/net/neighbour.h:527 [inline] ip_finish_output2+0x77f/0x2160 net/ipv4/ip_output.c:221 __ip_finish_output net/ipv4/ip_output.c:299 [inline] __ip_finish_output+0x396/0x640 net/ipv4/ip_output.c:281 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:309 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:423 dst_output include/net/dst.h:450 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0xd4/0x260 net/ipv4/ip_output.c:1555 udp_send_skb+0x6cd/0x11a0 net/ipv4/udp.c:967 udp_sendmsg+0x1bad/0x2740 net/ipv4/udp.c:1254 udpv6_sendmsg+0x14ea/0x2c40 net/ipv6/udp.c:1360 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:644 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x331/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmmsg+0x195/0x470 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575 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+0x44/0xae RIP: 0033:0x7f2e21606ae9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2e1eb5b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f2e2171a020 RCX: 00007f2e21606ae9 RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 00007f2e21660f25 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc39d1978f R14: 00007f2e1eb5b300 R15: 0000000000022000 Modules linked in: ---[ end trace 1068ddf8184ca009 ]--- RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:113 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 60 fc 8b 8a ff 74 24 10 ff 74 24 20 e8 86 65 c2 ff <0f> 0b e8 53 23 45 f8 4c 8b 64 24 18 e8 79 87 8b f8 48 c7 c1 00 09 RSP: 0018:ffffc90004cc6ad0 EFLAGS: 00010282 RAX: 0000000000000083 RBX: ffff88807f4333c0 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815ef908 RDI: fffff52000998d4c RBP: ffffffff8a8c0900 R08: 0000000000000083 R09: 0000000000000000 R10: ffffffff815e96ee R11: 0000000000000000 R12: ffffffff87bd970f R13: 0000000000000008 R14: ffff888028ec4000 R15: 00000000000000c0 FS: 00007f2e1eb5b700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31f23000 CR3: 0000000038832000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400