------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at net/mptcp/subflow.c:1519 subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1519
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
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/0x7c0 net/mptcp/subflow.c:1519
Code: 89 ee e8 d8 27 3b f6 40 84 ed 75 21 e8 ee 2c 3b f6 44 89 fe bf 07 00 00 00 e8 21 28 3b f6 41 83 ff 07 74 09 e8 d6 2c 3b f6 90 <0f> 0b 90 e8 cd 2c 3b f6 48 89 df e8 e5 ad ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc90000007578 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888025b7bfc0 RCX: ffffffff8b80709f
RDX: ffffffff8e2977c0 RSI: ffffffff8b8070aa RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000004 R11: ffffffff9b0521a0 R12: ffff888057498c00
R13: 1ffff92000000eaf R14: ffff8880258d4800 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff8880d66b2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd01af74b40 CR3: 000000002dbb2000 CR4: 0000000000352ef0
DR0: 0000000000000aa5 DR1: 00000000000000b4 DR2: 0000000000000008
DR3: 00000000000039dd DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 tcp_data_queue+0x13b0/0x4f90 net/ipv4/tcp_input.c:5197
 tcp_rcv_state_process+0xfdf/0x4ec0 net/ipv4/tcp_input.c:6922
 tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1949
 tcp_v4_rcv+0x2ee1/0x4640 net/ipv4/tcp_ipv4.c:2368
 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:239
 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:260
 dst_input include/net/dst.h:471 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:454 [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:574
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5991
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6104
 process_backlog+0x442/0x15e0 net/core/dev.c:6456
 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7506
 napi_poll net/core/dev.c:7569 [inline]
 net_rx_action+0xa9f/0xfe0 net/core/dev.c:7696
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 5d 61 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 36 15 00 fb f4 <e9> cc 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e08 EFLAGS: 00000282
RAX: 0000000000141907 RBX: 0000000000000000 RCX: ffffffff8b94db49
RDX: 0000000000000000 RSI: ffffffff8de52d59 RDI: ffffffff8c163400
RBP: fffffbfff1c52ef8 R08: 0000000000000001 R09: ffffed100d486655
R10: ffff88806a4332ab R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8e2977c0 R14: ffffffff90ab7690 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 rest_init+0x16b/0x2b0 init/main.c:744
 start_kernel+0x3ee/0x4d0 init/main.c:1097
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x148
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	02 c3                	add    %bl,%al
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	0f 1f 00             	nopl   (%rax)
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	f3 0f 1e fa          	endbr64
  1d:	eb 07                	jmp    0x26
  1f:	0f 00 2d d3 36 15 00 	verw   0x1536d3(%rip)        # 0x1536f9
  26:	fb                   	sti
  27:	f4                   	hlt
* 28:	e9 cc 09 03 00       	jmp    0x309f9 <-- trapping instruction
  2d:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  34:	00 00 00
  37:	66 90                	xchg   %ax,%ax
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop