------------[ cut here ]------------
WARNING: net/mptcp/subflow.c:1527 at subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527, CPU#0: kworker/u32:28/11953
Modules linked in:
CPU: 0 UID: 0 PID: 11953 Comm: kworker/u32:28 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: krdsd rds_tcp_accept_worker
RIP: 0010:subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527
Code: 89 ee e8 a8 5f 5d f6 40 84 ed 75 21 e8 5e 65 5d f6 44 89 fe bf 07 00 00 00 e8 f1 5f 5d f6 41 83 ff 07 74 09 e8 46 65 5d f6 90 <0f> 0b 90 e8 3d 65 5d f6 48 89 df e8 f5 ac ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc900000074d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888028a8dcc0 RCX: ffffffff8b60f0df
RDX: ffff888051c7a4c0 RSI: ffffffff8b60f0ea RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 000000000000000b R11: ffff888051c7aff0 R12: ffff88805a229900
R13: 1ffff92000000e9b R14: ffff888012c8b800 R15: 000000000000000b
FS:  0000000000000000(0000) GS:ffff8880976fd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f73f97d8 CR3: 000000005b3dc000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 tcp_data_ready+0x114/0x5a0 net/ipv4/tcp_input.c:5371
 tcp_data_queue+0x1ac2/0x4ff0 net/ipv4/tcp_input.c:5461
 tcp_rcv_state_process+0xfb6/0x6540 net/ipv4/tcp_input.c:7185
 tcp_v6_do_rcv+0x7b8/0x1dc0 net/ipv6/tcp_ipv6.c:1630
 tcp_v6_rcv+0x2ab5/0x48f0 net/ipv6/tcp_ipv6.c:1877
 ip6_protocol_deliver_rcu+0x188/0x1520 net/ipv6/ip6_input.c:438
 ip6_input_finish+0x1e4/0x4b0 net/ipv6/ip6_input.c:489
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip6_input+0x105/0x2f0 net/ipv6/ip6_input.c:500
 dst_input include/net/dst.h:474 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ipv6_rcv+0x264/0x650 net/ipv6/ip6_input.c:311
 __netif_receive_skb_one_core+0x12d/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+0x219/0x950 kernel/softirq.c:622
 do_softirq kernel/softirq.c:523 [inline]
 do_softirq+0xb2/0xf0 kernel/softirq.c:510
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 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+0x797/0x4650 net/core/dev.c:4844
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 neigh_hh_output include/net/neighbour.h:540 [inline]
 neigh_output include/net/neighbour.h:554 [inline]
 ip6_finish_output2+0x1184/0x1cf0 net/ipv6/ip6_output.c:136
 __ip6_finish_output+0x3cd/0x1010 net/ipv6/ip6_output.c:209
 ip6_finish_output net/ipv6/ip6_output.c:220 [inline]
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x253/0x710 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:464 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip6_xmit+0x1512/0x23f0 net/ipv6/ip6_output.c:371
 inet6_csk_xmit+0x444/0x7f0 net/ipv6/inet6_connection_sock.c:120
 __tcp_transmit_skb+0x1d67/0x48b0 net/ipv4/tcp_output.c:1631
 tcp_transmit_skb net/ipv4/tcp_output.c:1649 [inline]
 tcp_write_xmit+0x12aa/0x8710 net/ipv4/tcp_output.c:3002
 __tcp_push_pending_frames+0xaf/0x3c0 net/ipv4/tcp_output.c:3185
 tcp_send_fin+0x11f/0x10e0 net/ipv4/tcp_output.c:3808
 __tcp_close+0xa46/0x1120 net/ipv4/tcp.c:3208
 tcp_close+0x28/0x120 net/ipv4/tcp.c:3299
 inet_release+0xed/0x200 net/ipv4/af_inet.c:437
 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:487
 __sock_release net/socket.c:662 [inline]
 sock_release+0x91/0x1d0 net/socket.c:690
 rds_tcp_accept_one+0x31c/0xac0 net/rds/tcp_listen.c:214
 rds_tcp_accept_worker+0x59/0x80 net/rds/tcp.c:529
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 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>