------------[ cut here ]------------ WARNING: CPU: 1 PID: 9612 at net/mptcp/protocol.c:695 __mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695 Modules linked in: CPU: 1 UID: 0 PID: 9612 Comm: syz.0.857 Not tainted 6.11.0-syzkaller-10547-g684a64bf32b6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695 Code: 0f b6 dc 31 ff 89 de e8 45 ca e8 f5 89 d8 48 81 c4 50 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 28 c7 e8 f5 90 <0f> 0b 90 e9 47 ff ff ff e8 1a c7 e8 f5 90 0f 0b 90 e9 99 e0 ff ff RSP: 0018:ffffc90000a17d18 EFLAGS: 00010246 RAX: ffffffff8babee18 RBX: 00000000000002e8 RCX: ffff88802ce39e00 RDX: 0000000000000100 RSI: 00000000000081e5 RDI: 00000000000002e8 RBP: 1ffff1100f48561e R08: ffffffff8babde12 R09: 1ffff1100d4c761c R10: dffffc0000000000 R11: ffffed100d4c761d R12: 0000000000000000 R13: dffffc0000000000 R14: 00000000e0f7a5d1 R15: 00000000000081e5 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2d98b5 CR3: 0000000067d7e000 CR4: 00000000003506f0 DR0: 0000000000002d8e DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: move_skbs_to_msk net/mptcp/protocol.c:811 [inline] mptcp_data_ready+0x29c/0xa90 net/mptcp/protocol.c:854 subflow_data_ready+0x34a/0x920 net/mptcp/subflow.c:1490 tcp_data_queue+0x20fd/0x76c0 net/ipv4/tcp_input.c:5283 tcp_rcv_established+0xfba/0x2020 net/ipv4/tcp_input.c:6237 tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915 tcp_v4_rcv+0x2dc0/0x37f0 net/ipv4/tcp_ipv4.c:2350 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__preempt_count_sub arch/x86/include/asm/preempt.h:84 [inline] RIP: 0010:preempt_count_sub+0x5d/0x170 kernel/sched/core.c:5821 Code: 22 65 8b 05 ed d2 a0 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 27 81 fb fe 00 00 00 77 07 0f b6 c0 85 c0 74 5f 65 8b 05 cb d2 a0 7e db 65 01 1d c2 d2 a0 7e 5b 41 5e c3 cc cc cc cc 90 e8 6c 10 55 RSP: 0018:ffffc90003a97528 EFLAGS: 00000202 RAX: 0000000080000001 RBX: 0000000000000001 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8c0aca40 RDI: 0000000000000001 RBP: ffffc90003a975d0 R08: ffffffff942687f7 R09: 1ffffffff284d0fe R10: dffffc0000000000 R11: fffffbfff284d0ff R12: dffffc0000000000 R13: 1ffff92000752ea8 R14: dffffc0000000000 R15: 0000000000000246 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xdd/0x140 kernel/locking/spinlock.c:194 __debug_check_no_obj_freed lib/debugobjects.c:998 [inline] debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1019 slab_free_hook mm/slub.c:2274 [inline] slab_free mm/slub.c:4580 [inline] kmem_cache_free+0x11f/0x420 mm/slub.c:4682 exit_mmap+0x5c6/0xc40 mm/mmap.c:1888 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x176f/0x1810 kernel/signal.c:2936 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0121d7def9 Code: Unable to access opcode bytes at 0x7f0121d7decf. RSP: 002b:00007f0122b7c0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f0121f35f88 RCX: 00007f0121d7def9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0121f35f88 RBP: 00007f0121f35f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0121f35f8c R13: 0000000000000000 R14: 00007f012205f940 R15: 00007f012205fa28 ---------------- Code disassembly (best guess): 0: 22 65 8b and -0x75(%rbp),%ah 3: 05 ed d2 a0 7e add $0x7ea0d2ed,%eax 8: 89 c1 mov %eax,%ecx a: 81 e1 ff ff ff 7f and $0x7fffffff,%ecx 10: 39 d9 cmp %ebx,%ecx 12: 7c 27 jl 0x3b 14: 81 fb fe 00 00 00 cmp $0xfe,%ebx 1a: 77 07 ja 0x23 1c: 0f b6 c0 movzbl %al,%eax 1f: 85 c0 test %eax,%eax 21: 74 5f je 0x82 23: 65 8b 05 cb d2 a0 7e mov %gs:0x7ea0d2cb(%rip),%eax # 0x7ea0d2f5 * 2a: f7 db neg %ebx <-- trapping instruction 2c: 65 01 1d c2 d2 a0 7e add %ebx,%gs:0x7ea0d2c2(%rip) # 0x7ea0d2f5 33: 5b pop %rbx 34: 41 5e pop %r14 36: c3 ret 37: cc int3 38: cc int3 39: cc int3 3a: cc int3 3b: 90 nop 3c: e8 .byte 0xe8 3d: 6c insb (%dx),%es:(%rdi) 3e: 10 .byte 0x10 3f: 55 push %rbp