------------[ cut here ]------------
WARNING: CPU: 0 PID: 23684 at net/mptcp/subflow.c:1520 subflow_data_ready+0x4b8/0x7e0 net/mptcp/subflow.c:1519
Modules linked in:
CPU: 0 UID: 0 PID: 23684 Comm: syz.9.4959 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:subflow_data_ready+0x4b8/0x7e0 net/mptcp/subflow.c:1519
Code: 0f 0b 90 90 e9 bc fc ff ff e8 14 32 59 f6 48 89 df 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 6e 0e 00 00 e8 f9 31 59 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:ffffc90000007140 EFLAGS: 00010246
RAX: ffffffff8b667cc7 RBX: ffff88804e0f8000 RCX: ffff8880792f0000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88804e0a392f R09: 1ffff11009c14725
R10: dffffc0000000000 R11: ffffed1009c14726 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88804e0a3000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33c24000 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 tcp_data_queue+0x548/0x6380 net/ipv4/tcp_input.c:5197
 tcp_rcv_state_process+0x2767/0x4140 net/ipv4/tcp_input.c:6922
 tcp_v4_do_rcv+0x3f2/0xce0 net/ipv4/tcp_ipv4.c:1949
 tcp_v4_rcv+0x26a6/0x2f40 net/ipv4/tcp_ipv4.c:2368
 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:5991 [inline]
 __netif_receive_skb+0x143/0x380 net/core/dev.c:6104
 process_backlog+0x60e/0x14f0 net/core/dev.c:6456
 __napi_poll+0xc4/0x360 net/core/dev.c:7506
 napi_poll net/core/dev.c:7569 [inline]
 net_rx_action+0x707/0xe30 net/core/dev.c:7696
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 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+0xa6/0xc0 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:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d 34 86 fe 0b 48 89 de 5b e9 13 ac 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 e0 a0 92 65 8b 15 58 31 e1 10 81 e2 00 01 ff 00
RSP: 0018:ffffc90012757098 EFLAGS: 00000293
RAX: ffffffff821a6eb6 RBX: ffff888027cb07b0 RCX: 0000000000000000
RDX: ffff8880792f0000 RSI: 000000000000001b RDI: 000000000000001f
RBP: ffffc90012757328 R08: ffffea0001d41847 R09: 1ffffd40003a8308
R10: dffffc0000000000 R11: fffff940003a8309 R12: 1ffff11004f960f6
R13: dffffc0000000000 R14: 000000000000001b R15: 00000000000000f4
 free_pages_and_swap_cache+0x1a6/0x520 mm/swap_state.c:258
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
 tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
 zap_pte_range mm/memory.c:1765 [inline]
 zap_pmd_range mm/memory.c:1818 [inline]
 zap_pud_range mm/memory.c:1847 [inline]
 zap_p4d_range mm/memory.c:1868 [inline]
 unmap_page_range+0x3b31/0x4370 mm/memory.c:1889
 unmap_single_vma mm/memory.c:1932 [inline]
 unmap_vmas+0x399/0x580 mm/memory.c:1976
 exit_mmap+0x248/0xb50 mm/mmap.c:1280
 __mmput+0x118/0x430 kernel/fork.c:1129
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:949
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7febe5d8eec9
Code: Unable to access opcode bytes at 0x7febe5d8ee9f.
RSP: 002b:00007febe6c660e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007febe5fe5fa8 RCX: 00007febe5d8eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007febe5fe5fa8
RBP: 00007febe5fe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007febe5fe6038 R14: 00007fffc3b58460 R15: 00007fffc3b58548
 </TASK>
----------------
Code disassembly (best guess):
   0:	8b 3d 34 86 fe 0b    	mov    0xbfe8634(%rip),%edi        # 0xbfe863a
   6:	48 89 de             	mov    %rbx,%rsi
   9:	5b                   	pop    %rbx
   a:	e9 13 ac 58 00       	jmp    0x58ac22
   f:	cc                   	int3
  10:	cc                   	int3
  11:	cc                   	int3
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	f3 0f 1e fa          	endbr64
  26:	48 8b 04 24          	mov    (%rsp),%rax
* 2a:	65 48 8b 0c 25 08 e0 	mov    %gs:0xffffffff92a0e008,%rcx <-- trapping instruction
  31:	a0 92
  33:	65 8b 15 58 31 e1 10 	mov    %gs:0x10e13158(%rip),%edx        # 0x10e13192
  3a:	81 e2 00 01 ff 00    	and    $0xff0100,%edx