------------[ cut here ]------------
WARNING: CPU: 0 PID: 5876 at net/mptcp/subflow.c:1520 subflow_data_ready+0x4b8/0x7e0
Modules linked in:
CPU: 0 UID: 0 PID: 5876 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:subflow_data_ready+0x4b8/0x7e0
Code: 0f 0b 90 90 e9 bc fc ff ff e8 24 95 58 f6 48 89 df 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 6e 0e 00 00 e8 09 95 58 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:ffffc90000007160 EFLAGS: 00010246
RAX: ffffffff8b671887 RBX: ffff88803af15b00 RCX: ffff88801ff09cc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88811b862d37 R09: 1ffff1102370c5a6
R10: dffffc0000000000 R11: ffffed102370c5a7 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88811b862400 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f956f3de440 CR3: 0000000114cea000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 tcp_data_queue+0x54b/0x6450
 tcp_rcv_state_process+0x23a4/0x44d0
 tcp_v4_do_rcv+0x3f2/0xce0
 tcp_v4_rcv+0x252a/0x2dc0
 ip_protocol_deliver_rcu+0x221/0x440
 ip_local_deliver_finish+0x3bb/0x6f0
 NF_HOOK+0x30c/0x3a0
 NF_HOOK+0x30c/0x3a0
 __netif_receive_skb+0x143/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110
Code: 74 05 e8 5b b8 49 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e3 5e 12 f6 65 8b 05 6c 31 23 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000409ede0 EFLAGS: 00000206
RAX: ea01496c8cbeb400 RBX: 0000000000000246 RCX: ea01496c8cbeb400
RDX: 0000000000000006 RSI: ffffffff8d9ba1ca RDI: 0000000000000001
RBP: ffffc9000409ee70 R08: ffffffff8fa38f37 R09: 1ffffffff1f471e6
R10: dffffc0000000000 R11: fffffbfff1f471e7 R12: dffffc0000000000
R13: ffffffff8e13f400 R14: ffffffff8e13f400 R15: 1ffff92000813dbc
 rcu_preempt_deferred_qs_irqrestore+0x89c/0xce0
 rcu_read_unlock_special+0x3a2/0x4b0
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 kernfs_put+0x19e/0x480
 kernfs_remove_by_name_ns+0xb7/0x130
 sysfs_remove_group+0xfc/0x2c0
 sysfs_remove_groups+0x54/0xb0
 ib_free_port_attrs+0xc5/0x3b0
 rdma_dev_exit_net+0x1d8/0x340
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
