------------[ cut here ]------------
WARNING: net/mptcp/subflow.c:1527 at subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527, CPU#0: ksoftirqd/0/15
Modules linked in:
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Tainted: G     U       L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527
Code: 89 ee e8 38 8f 6c f6 40 84 ed 75 21 e8 de 94 6c f6 44 89 fe bf 07 00 00 00 e8 81 8f 6c f6 41 83 ff 07 74 09 e8 c6 94 6c f6 90 <0f> 0b 90 e8 bd 94 6c f6 48 89 df e8 35 ae ff ff 31 ff 89 c5 89 c6
RSP: 0000:ffffc90000147308 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88808b4f0000 RCX: ffffffff8b51177f
RDX: ffff88801da9bd00 RSI: ffffffff8b51178a RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000004 R11: 000000009208b4d3 R12: ffff888035ab0c00
R13: 1ffff92000028e61 R14: ffff88805c72f400 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff88812495b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8c61de769d CR3: 0000000098828000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 tcp_data_ready+0x114/0x5a0 net/ipv4/tcp_input.c:5371
 tcp_data_queue+0x1aa6/0x5000 net/ipv4/tcp_input.c:5461
 tcp_rcv_state_process+0xfb6/0x6490 net/ipv4/tcp_input.c:7185
 tcp_v4_do_rcv+0x68e/0x10a0 net/ipv4/tcp_ipv4.c:1904
 tcp_v4_rcv+0x3077/0x4db0 net/ipv4/tcp_ipv4.c:2324
 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:241
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:474 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:573
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6137
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6250
 process_backlog+0x4a2/0x1650 net/core/dev.c:6602
 __napi_poll.constprop.0+0xb3/0x540 net/core/dev.c:7666
 napi_poll net/core/dev.c:7729 [inline]
 net_rx_action+0x9f9/0xfa0 net/core/dev.c:7881
 handle_softirqs+0x219/0x8b0 kernel/softirq.c:622
 run_ksoftirqd kernel/softirq.c:1063 [inline]
 run_ksoftirqd+0x3a/0x60 kernel/softirq.c:1055
 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>