Kernel bug: WARNING in subflow_data_ready (4)
Subsystem: mptcp
Status: fixed

Crash report:
------------[ cut here ]------------
WARNING: net/mptcp/subflow.c:1528 at subflow_data_ready+0x49b/0x7c0 net/mptcp/subflow.c:1527, CPU#1: kworker/u8:10/3067
Modules linked in:
CPU: 1 UID: 0 PID: 3067 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: krdsd rds_tcp_accept_worker
RIP: 0010:subflow_data_ready+0x49b/0x7c0 net/mptcp/subflow.c:1527
Code: 48 0f b9 3a e9 c9 fc ff ff e8 71 33 7b f6 48 89 df 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 6b 0e 00 00 e8 56 33 7b f6 90 <0f> 0b 90 e9 f2 fd ff ff 90 0f 0b 90 43 0f b6 04 2f 84 c0 0f 85 a1
RSP: 0018:ffffc90000a08240 EFLAGS: 00010246
RAX: ffffffff8b45c22a RBX: ffff88802b45cf80 RCX: ffff88802fd13d00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880334195cf R09: 1ffff110066832b9
R10: dffffc0000000000 R11: ffffed10066832ba R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888033418c80 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558bae8808 CR3: 000000007b568000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 tcp_data_queue+0x1e14/0x5e30 net/ipv4/tcp_input.c:5461
 tcp_rcv_state_process+0x23a4/0x4520 net/ipv4/tcp_input.c:7185
 tcp_v6_do_rcv+0xbef/0x1ba0 net/ipv6/tcp_ipv6.c:1630
 tcp_v6_rcv+0x2247/0x2ae0 net/ipv6/tcp_ipv6.c:1877
 ip6_protocol_deliver_rcu+0xcb0/0x15c0 net/ipv6/ip6_input.c:438
 ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:489
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:6137 [inline]
 __netif_receive_skb+0xd3/0x380 net/core/dev.c:6250
 process_backlog+0x54f/0x1340 net/core/dev.c:6602
 __napi_poll+0xae/0x320 net/core/dev.c:7666
 napi_poll net/core/dev.c:7729 [inline]
 net_rx_action+0x64a/0xe00 net/core/dev.c:7881
 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline]
 __dev_queue_xmit+0x1955/0x3140 net/core/dev.c:4844
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ip6_xmit+0x11b5/0x1970 net/ipv6/ip6_output.c:371
 inet6_csk_xmit+0x4db/0x780 net/ipv6/inet6_connection_sock.c:120
 __tcp_transmit_skb+0x2092/0x3aa0 net/ipv4/tcp_output.c:1631
 tcp_transmit_skb net/ipv4/tcp_output.c:1649 [inline]
 tcp_write_xmit+0x16e8/0x6980 net/ipv4/tcp_output.c:3002
 __tcp_push_pending_frames+0x97/0x380 net/ipv4/tcp_output.c:3185
 __tcp_close+0x617/0xfe0 net/ipv4/tcp.c:3208
 tcp_close+0x28/0x110 net/ipv4/tcp.c:3299
 inet_release+0x144/0x190 net/ipv4/af_inet.c:437
 __sock_release net/socket.c:662 [inline]
 sock_release+0x85/0x150 net/socket.c:690
 rds_tcp_accept_one+0x71a/0x930 net/rds/tcp_listen.c:214
 rds_tcp_accept_worker+0x3e/0xa0 net/rds/tcp.c:529
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>