------------[ cut here ]------------
WARNING: CPU: 1 PID: 18014 at net/mptcp/subflow.c:1520 subflow_data_ready+0x4b8/0x7e0 net/mptcp/subflow.c:1519
Modules linked in:
CPU: 1 UID: 0 PID: 18014 Comm: syz.3.3219 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:subflow_data_ready+0x4b8/0x7e0 net/mptcp/subflow.c:1519
Code: 0f 0b 90 90 e9 bc fc ff ff e8 c4 f1 8c f6 48 89 df 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 6e 0e 00 00 e8 a9 f1 8c f6 90 <0f> 0b 90 e9 e5 fd ff ff 90 0f 0b 90 43 0f b6 04 2f 84 c0 0f 85 a1
RSP: 0018:ffffc90019e87720 EFLAGS: 00010293
RAX: ffffffff8b331207 RBX: ffff88807c53de80 RCX: ffff88807d568000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff888030b53b3f R09: 1ffff1100616a767
R10: dffffc0000000000 R11: ffffed100616a768 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888030b53200 R15: 0000000000000000
FS:  00007f97172896c0(0000) GS:ffff888126238000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9717268d58 CR3: 0000000044d52000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 tcp_data_queue+0x201e/0x64a0 net/ipv4/tcp_input.c:5445
 tcp_rcv_established+0x1335/0x2670 net/ipv4/tcp_input.c:6448
 tcp_v6_do_rcv+0x8eb/0x1ba0 net/ipv6/tcp_ipv6.c:1652
 sk_backlog_rcv include/net/sock.h:1158 [inline]
 __release_sock+0x1b8/0x3a0 net/core/sock.c:3180
 release_sock+0x5f/0x1f0 net/core/sock.c:3735
 mptcp_connect+0x649/0x830 net/mptcp/protocol.c:3854
 __inet_stream_connect+0x2ae/0xe70 net/ipv4/af_inet.c:679
 inet_stream_connect+0x66/0xa0 net/ipv4/af_inet.c:750
 __sys_connect_file net/socket.c:2102 [inline]
 __sys_connect+0x316/0x440 net/socket.c:2121
 __do_sys_connect net/socket.c:2127 [inline]
 __se_sys_connect net/socket.c:2124 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2124
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f971638f749
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:00007f9717289038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f97165e6090 RCX: 00007f971638f749
RDX: 000000000000001c RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007f9716413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f97165e6128 R14: 00007f97165e6090 R15: 00007fffc9bac718
 </TASK>