------------[ cut here ]------------
WARNING: CPU: 2 PID: 6288 at net/mptcp/protocol.c:695 __mptcp_move_skbs_from_subflow+0x1627/0x24d0 net/mptcp/protocol.c:695
Modules linked in:
CPU: 2 UID: 0 PID: 6288 Comm: syz.3.307 Not tainted 6.11.0-syzkaller-11558-g075dbe9f6e3c #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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 ca bb 8c f6 90 <0f> 0b 90 e9 49 f3 ff ff e8 bc bb 8c f6 90 0f 0b 90 e9 df f0 ff ff
RSP: 0018:ffffc90000858408 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000c0d8 RCX: ffffffff8b002892
RDX: ffff8880259dc880 RSI: ffffffff8b0035f6 RDI: 0000000000000004
RBP: ffffc90000858528 R08: 0000000000000004 R09: 000000000000c0d8
R10: 000000000000bf68 R11: 0000000000000000 R12: ffff88802f1180e8
R13: 0000000000000001 R14: ffff88802f118000 R15: dffffc0000000000
FS:  00007fcb70dff6c0(0000) GS:ffff88806a800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002004c000 CR3: 0000000029eae000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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:1490
 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:6237
 tcp_v4_do_rcv+0x5ca/0xa90 net/ipv4/tcp_ipv4.c:1915
 tcp_v4_rcv+0x33a8/0x4390 net/ipv4/tcp_ipv4.c:2350
 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+0x2c3/0x5d0 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5662
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5775
 process_backlog+0x443/0x15f0 net/core/dev.c:6107
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6771
 napi_poll net/core/dev.c:6840 [inline]
 net_rx_action+0xa92/0x1010 net/core/dev.c:6962
 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554
 do_softirq kernel/softirq.c:455 [inline]
 do_softirq+0xb2/0xf0 kernel/softirq.c:442
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 unlock_sock_fast include/net/sock.h:1670 [inline]
 unlock_sock_fast include/net/sock.h:1662 [inline]
 mptcp_rcv_space_adjust net/mptcp/protocol.c:2068 [inline]
 mptcp_recvmsg+0x2189/0x2600 net/mptcp/protocol.c:2271
 inet_recvmsg+0x469/0x6a0 net/ipv4/af_inet.c:885
 sock_recvmsg_nosec net/socket.c:1052 [inline]
 sock_recvmsg+0x1b2/0x250 net/socket.c:1074
 __sys_recvfrom+0x1a5/0x2e0 net/socket.c:2261
 __do_sys_recvfrom net/socket.c:2279 [inline]
 __se_sys_recvfrom net/socket.c:2275 [inline]
 __x64_sys_recvfrom+0xe0/0x1c0 net/socket.c:2275
 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: 0033:0x7fcb7137df39
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:00007fcb70dff038 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: ffffffffffffffda RBX: 00007fcb71536058 RCX: 00007fcb7137df39
RDX: fffffffffffffecb RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007fcb713f0216 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000500 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcb71536058 R15: 00007ffd920dd378
 </TASK>