================================ WARNING: inconsistent lock state syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.4.1742/12735 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888077f3e260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff888077f3e260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 lock_sock_nested+0x41/0x100 net/core/sock.c:3837 lock_sock include/net/sock.h:1713 [inline] x25_release+0xa0/0x3d0 net/x25/af_x25.c:632 __sock_release+0xa0/0x1f0 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 226 hardirqs last enabled at (226): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (225): [] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455 softirqs last enabled at (92): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last enabled at (92): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last enabled at (92): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 softirqs last disabled at (189): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last disabled at (189): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last disabled at (189): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sk_lock-AF_X25); lock(sk_lock-AF_X25); *** DEADLOCK *** locks held by syz.4.1742/12735: 4, last CPU#0: #0: ffff88803468a9f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff88803468a9f8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290 #2: ffff88803281bc18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline] #2: ffff88803281bc18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6321 stack backtrace: CPU: 0 UID: 0 PID: 12735 Comm: syz.4.1742 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_usage_bug+0x28c/0x2e0 kernel/locking/lockdep.c:4086 valid_state+0xbe/0xf0 kernel/locking/lockdep.c:4100 mark_lock_irq+0x36/0x380 kernel/locking/lockdep.c:4311 mark_lock+0x117/0x190 kernel/locking/lockdep.c:4797 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x71e/0x2de0 kernel/locking/lockdep.c:5242 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 lock_sock_nested+0x41/0x100 net/core/sock.c:3837 lock_sock include/net/sock.h:1713 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6297 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6322 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7830 napi_poll net/core/dev.c:7893 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8050 handle_softirqs+0x226/0x860 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__nr_to_section include/linux/mmzone.h:2067 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:2193 [inline] RIP: 0010:pfn_valid+0x7b/0x490 include/linux/mmzone.h:2275 Code: 0b 0c 61 18 48 85 c0 74 40 4c 89 f1 48 c1 e9 16 48 8d 1c c8 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 45 06 f4 ff <4c> 8b 3b 4d 85 ff 74 1e 4c 89 f3 48 c1 eb 0f e8 d1 01 84 ff 83 e3 RSP: 0018:ffffc9000545f318 EFLAGS: 00000246 RAX: 1ffff11047ffc600 RBX: ffff88823ffe3000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000000639f3 RDI: 0000000400000000 RBP: ffffc9000545f690 R08: ffffea00018e7cc7 R09: 1ffffd400031cf98 R10: dffffc0000000000 R11: fffff9400031cf99 R12: dffffc0000000000 R13: 00007f582ba00000 R14: 00000000000639f3 R15: 00007f582b9ee000 page_table_check_clear+0x21/0x500 mm/page_table_check.c:70 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:879 [inline] zap_present_folio_ptes mm/memory.c:1779 [inline] zap_present_ptes mm/memory.c:1861 [inline] do_zap_pte_range mm/memory.c:1963 [inline] zap_pte_range mm/memory.c:2065 [inline] zap_pmd_range mm/memory.c:2151 [inline] zap_pud_range mm/memory.c:2179 [inline] zap_p4d_range mm/memory.c:2200 [inline] __zap_vma_range+0x3a12/0x4f80 mm/memory.c:2240 unmap_vmas+0x390/0x550 mm/memory.c:2309 exit_mmap+0x293/0x9f0 mm/mmap.c:1315 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:618 do_exit+0x6cd/0x2360 kernel/exit.c:1000 do_group_exit+0x22d/0x2f0 kernel/exit.c:1155 get_signal+0x121b/0x12c0 kernel/signal.c:3112 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f582c59e159 Code: Unable to access opcode bytes at 0x7f582c59e12f. RSP: 002b:00007f582a7d50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f582c826098 RCX: 00007f582c59e159 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f582c826098 RBP: 00007f582c826090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f582c826128 R14: 00007ffe2a4d58a0 R15: 00007ffe2a4d5988 BUG: sleeping function called from invalid context at net/core/sock.c:3839 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 12735, name: syz.4.1742 preempt_count: 101, expected: 0 RCU nest depth: 2, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [<0000000000000000>] 0x0 CPU: 0 UID: 0 PID: 12735 Comm: syz.4.1742 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x36a/0x4c0 kernel/sched/core.c:9264 lock_sock_nested+0x56/0x100 net/core/sock.c:3839 lock_sock include/net/sock.h:1713 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6297 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6322 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7830 napi_poll net/core/dev.c:7893 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8050 handle_softirqs+0x226/0x860 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__nr_to_section include/linux/mmzone.h:2067 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:2193 [inline] RIP: 0010:pfn_valid+0x7b/0x490 include/linux/mmzone.h:2275 Code: 0b 0c 61 18 48 85 c0 74 40 4c 89 f1 48 c1 e9 16 48 8d 1c c8 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 45 06 f4 ff <4c> 8b 3b 4d 85 ff 74 1e 4c 89 f3 48 c1 eb 0f e8 d1 01 84 ff 83 e3 RSP: 0018:ffffc9000545f318 EFLAGS: 00000246 RAX: 1ffff11047ffc600 RBX: ffff88823ffe3000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000000639f3 RDI: 0000000400000000 RBP: ffffc9000545f690 R08: ffffea00018e7cc7 R09: 1ffffd400031cf98 R10: dffffc0000000000 R11: fffff9400031cf99 R12: dffffc0000000000 R13: 00007f582ba00000 R14: 00000000000639f3 R15: 00007f582b9ee000 page_table_check_clear+0x21/0x500 mm/page_table_check.c:70 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:879 [inline] zap_present_folio_ptes mm/memory.c:1779 [inline] zap_present_ptes mm/memory.c:1861 [inline] do_zap_pte_range mm/memory.c:1963 [inline] zap_pte_range mm/memory.c:2065 [inline] zap_pmd_range mm/memory.c:2151 [inline] zap_pud_range mm/memory.c:2179 [inline] zap_p4d_range mm/memory.c:2200 [inline] __zap_vma_range+0x3a12/0x4f80 mm/memory.c:2240 unmap_vmas+0x390/0x550 mm/memory.c:2309 exit_mmap+0x293/0x9f0 mm/mmap.c:1315 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:618 do_exit+0x6cd/0x2360 kernel/exit.c:1000 do_group_exit+0x22d/0x2f0 kernel/exit.c:1155 get_signal+0x121b/0x12c0 kernel/signal.c:3112 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f582c59e159 Code: Unable to access opcode bytes at 0x7f582c59e12f. RSP: 002b:00007f582a7d50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f582c826098 RCX: 00007f582c59e159 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f582c826098 RBP: 00007f582c826090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f582c826128 R14: 00007ffe2a4d58a0 R15: 00007ffe2a4d5988 ---------------- Code disassembly (best guess): 0: 0b 0c 61 or (%rcx,%riz,2),%ecx 3: 18 48 85 sbb %cl,-0x7b(%rax) 6: c0 74 40 4c 89 shlb $0x89,0x4c(%rax,%rax,2) b: f1 int1 c: 48 c1 e9 16 shr $0x16,%rcx 10: 48 8d 1c c8 lea (%rax,%rcx,8),%rbx 14: 48 89 d8 mov %rbx,%rax 17: 48 c1 e8 03 shr $0x3,%rax 1b: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 20: 74 08 je 0x2a 22: 48 89 df mov %rbx,%rdi 25: e8 45 06 f4 ff call 0xfff4066f * 2a: 4c 8b 3b mov (%rbx),%r15 <-- trapping instruction 2d: 4d 85 ff test %r15,%r15 30: 74 1e je 0x50 32: 4c 89 f3 mov %r14,%rbx 35: 48 c1 eb 0f shr $0xf,%rbx 39: e8 d1 01 84 ff call 0xff84020f 3e: 83 .byte 0x83 3f: e3 .byte 0xe3