TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. Sending cookies. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 7960 at net/mptcp/protocol.c:695 __mptcp_move_skbs_from_subflow+0x1627/0x24d0 net/mptcp/protocol.c:695 Modules linked in: CPU: 1 UID: 0 PID: 7960 Comm: syz.2.491 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__mptcp_move_skbs_from_subflow+0x1627/0x24d0 net/mptcp/protocol.c:695 Code: 02 48 89 ea 83 e2 07 38 d0 7f 08 84 c0 0f 85 86 0d 00 00 c6 43 7f 00 e9 22 f0 ff ff 48 8b ac 24 a0 00 00 00 e8 0a 57 94 f6 90 <0f> 0b 90 e9 49 f3 ff ff e8 fc 56 94 f6 90 0f 0b 90 e9 df f0 ff ff RSP: 0018:ffffc90000a18408 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000081e5 RCX: ffffffff8af75be2 RDX: ffff888025d05a00 RSI: ffffffff8af76946 RDI: 0000000000000004 RBP: ffffc90000a18528 R08: 0000000000000004 R09: 00000000000081e5 R10: 00000000000055f0 R11: 0000000000000000 R12: ffff88802972be28 R13: 0000000000000000 R14: ffff88802972bd40 R15: dffffc0000000000 FS: 00007fca76ae46c0(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33004ff8 CR3: 000000004ccca000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: move_skbs_to_msk net/mptcp/protocol.c:811 [inline] mptcp_data_ready+0x30e/0x8e0 net/mptcp/protocol.c:854 subflow_data_ready+0x51d/0x7d0 net/mptcp/subflow.c:1486 tcp_data_ready+0x146/0x5b0 net/ipv4/tcp_input.c:5193 tcp_data_queue+0x1a6f/0x5280 net/ipv4/tcp_input.c:5283 tcp_rcv_established+0x8b1/0x21c0 net/ipv4/tcp_input.c:6230 tcp_v4_do_rcv+0x5ca/0xa90 net/ipv4/tcp_ipv4.c:1911 tcp_v4_rcv+0x33a8/0x4390 net/ipv4/tcp_ipv4.c:2346 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c5/0x5d0 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5661 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5775 process_backlog+0x443/0x15f0 net/core/dev.c:6108 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6963 handle_softirqs+0x216/0x8f0 kernel/softirq.c:554 do_softirq kernel/softirq.c:455 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:442 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x882/0x4300 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0x16fe/0x25e0 net/ipv4/ip_output.c:235 __ip_finish_output net/ipv4/ip_output.c:313 [inline] __ip_finish_output+0x49e/0x950 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:450 [inline] ip_local_out+0x33e/0x4a0 net/ipv4/ip_output.c:129 __ip_queue_xmit+0x747/0x1940 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2a4c/0x3dc0 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_mtu_probe net/ipv4/tcp_output.c:2546 [inline] tcp_write_xmit+0x809d/0x8490 net/ipv4/tcp_output.c:2751 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3014 tcp_push_pending_frames include/net/tcp.h:2106 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5707 [inline] tcp_rcv_established+0x93a/0x21c0 net/ipv4/tcp_input.c:6232 tcp_v4_do_rcv+0x5ca/0xa90 net/ipv4/tcp_ipv4.c:1911 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x31b/0x400 net/core/sock.c:3004 release_sock+0x5a/0x220 net/core/sock.c:3558 __mptcp_push_pending+0x400/0x560 net/mptcp/protocol.c:1625 mptcp_sendmsg+0x1960/0x1f20 net/mptcp/protocol.c:1910 inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x42c/0x4e0 net/socket.c:2204 __do_sys_sendto net/socket.c:2216 [inline] __se_sys_sendto net/socket.c:2212 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2212 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fca75d79eb9 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:00007fca76ae4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fca75f16058 RCX: 00007fca75d79eb9 RDX: 0000000000100b20 RSI: 0000000020000040 RDI: 0000000000000006 RBP: 00007fca75de793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fca75f16058 R15: 00007ffe4173e138