------------[ cut here ]------------ WARNING: CPU: 1 PID: 13633 at net/mptcp/subflow.c:1520 subflow_data_ready+0x4b8/0x7e0 net/mptcp/subflow.c:1519 Modules linked in: CPU: 1 UID: 0 PID: 13633 Comm: syz.2.2249 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 04 3f 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 e9 3e 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:ffffc90000a08140 EFLAGS: 00010246 RAX: ffffffff8b666ea7 RBX: ffff888021393fc0 RCX: ffff8880254d9e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88805574b92f R09: 1ffff1100aae9725 R10: dffffc0000000000 R11: ffffed100aae9726 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff88805574b000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb109974860 CR3: 000000000df36000 CR4: 00000000003526f0 Call Trace: tcp_data_queue+0x54b/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+0xc7/0x360 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 81 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9001b9af2b0 EFLAGS: 00000206 RAX: 91ca59582e713b00 RBX: 0000000000000000 RCX: 91ca59582e713b00 RDX: 0000000000000000 RSI: ffffffff8dba9961 RDI: ffffffff8be33f00 RBP: ffffffff822e57e7 R08: 0000000000000000 R09: ffffffff822e57e7 R10: dffffc0000000000 R11: fffff94000346441 R12: 0000000000000002 R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] page_table_check_clear+0x1a4/0x700 mm/page_table_check.c:77 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:725 [inline] zap_present_folio_ptes mm/memory.c:1499 [inline] zap_present_ptes mm/memory.c:1581 [inline] do_zap_pte_range mm/memory.c:1682 [inline] zap_pte_range mm/memory.c:1726 [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+0x3445/0x4370 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: 0033:0x7f98d818eec9 Code: Unable to access opcode bytes at 0x7f98d818ee9f. RSP: 002b:00007f98d90880e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f98d83e5fa8 RCX: 00007f98d818eec9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f98d83e5fa8 RBP: 00007f98d83e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f98d83e6038 R14: 00007ffe0e9ac710 R15: 00007ffe0e9ac7f8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 9c pushf 5: 8f 44 24 30 pop 0x30(%rsp) 9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp) 10: 00 11: 0f 85 cd 00 00 00 jne 0xe4 17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp) 1e: 00 1f: 74 01 je 0x22 21: fb sti 22: 65 48 8b 05 7b 81 03 mov %gs:0x1103817b(%rip),%rax # 0x110381a5 29: 11 * 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction 2f: 0f 85 f2 00 00 00 jne 0x127 35: 48 83 c4 60 add $0x60,%rsp 39: 5b pop %rbx 3a: 41 5c pop %r12 3c: 41 5d pop %r13 3e: 41 5e pop %r14