------------[ cut here ]------------
WARNING: net/mptcp/subflow.c:1527 at subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527, CPU#1: syz.2.1150/9913
Modules linked in:
CPU: 1 UID: 0 PID: 9913 Comm: syz.2.1150 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
RIP: 0010:subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527
Code: 89 ee e8 38 37 5b f6 40 84 ed 75 21 e8 ee 3c 5b f6 44 89 fe bf 07 00 00 00 e8 81 37 5b f6 41 83 ff 07 74 09 e8 d6 3c 5b f6 90 <0f> 0b 90 e8 cd 3c 5b f6 48 89 df e8 f5 ac ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc900006a04c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888027700000 RCX: ffffffff8b63a98f
RDX: ffff88805d584980 RSI: ffffffff8b63a99a RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000004 R11: ffff88805d5854b0 R12: ffff888029133e80
R13: 1ffff920000d4099 R14: ffff8880002ae800 R15: 0000000000000004
FS:  00007fea71dee6c0(0000) GS:ffff8880d69f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fea71dedf98 CR3: 000000005d6d1000 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:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kmem_cache_alloc_bulk+0x1d9/0x6c0 mm/slub.c:7431
Code: 85 d2 74 0a 80 7a 30 01 74 04 90 0f 0b 90 c6 42 30 00 41 f7 c4 00 02 00 00 0f 85 86 02 00 00 9c 58 f6 c4 02 0f 85 27 03 00 00 <45> 8b 4d 34 48 8b 4c 24 60 49 89 d8 4c 89 ef 8b 74 24 1c ba ff ff
RSP: 0018:ffffc900211e7658 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88806a541840 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: ffffffff8bf2b400
RBP: 000000000000000e R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088b4d7 R11: ffff88801c6a7090 R12: 0000000000000283
R13: ffff88801cab6780 R14: 0000000000000020 R15: 000000000000000e
 refill_sheaf mm/slub.c:2650 [inline]
 alloc_full_sheaf mm/slub.c:2671 [inline]
 __pcs_replace_empty_main+0x2b2/0x4e0 mm/slub.c:5033
 alloc_from_pcs mm/slub.c:5121 [inline]
 slab_alloc_node mm/slub.c:5248 [inline]
 kmem_cache_alloc_noprof+0x5af/0x770 mm/slub.c:5270
 vm_area_alloc+0x1f/0x160 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2469 [inline]
 __mmap_region+0x107a/0x2a00 mm/vma.c:2708
 mmap_region+0x32b/0x3f0 mm/vma.c:2786
 do_mmap+0xa3e/0x1210 mm/mmap.c:558
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:604
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea73b8f803
Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7
RSP: 002b:00007fea71dedfc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fea73de5fa0 RCX: 00007fea73b8f803
RDX: 0000000000000003 RSI: 0000000000002440 RDI: 0000000000000000
RBP: 0000200000000880 R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000008001 R11: 0000000000000246 R12: 0000000000000009
R13: 0000200000000000 R14: 00000000000000d2 R15: 0000200000000080
 </TASK>
----------------
Code disassembly (best guess):
   0:	85 d2                	test   %edx,%edx
   2:	74 0a                	je     0xe
   4:	80 7a 30 01          	cmpb   $0x1,0x30(%rdx)
   8:	74 04                	je     0xe
   a:	90                   	nop
   b:	0f 0b                	ud2
   d:	90                   	nop
   e:	c6 42 30 00          	movb   $0x0,0x30(%rdx)
  12:	41 f7 c4 00 02 00 00 	test   $0x200,%r12d
  19:	0f 85 86 02 00 00    	jne    0x2a5
  1f:	9c                   	pushf
  20:	58                   	pop    %rax
  21:	f6 c4 02             	test   $0x2,%ah
  24:	0f 85 27 03 00 00    	jne    0x351
* 2a:	45 8b 4d 34          	mov    0x34(%r13),%r9d <-- trapping instruction
  2e:	48 8b 4c 24 60       	mov    0x60(%rsp),%rcx
  33:	49 89 d8             	mov    %rbx,%r8
  36:	4c 89 ef             	mov    %r13,%rdi
  39:	8b 74 24 1c          	mov    0x1c(%rsp),%esi
  3d:	ba                   	.byte 0xba
  3e:	ff                   	(bad)
  3f:	ff                   	.byte 0xff