================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.9.3610/18525 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88807f614260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff88807f614260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775 {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_listen+0x47/0x180 net/x25/af_x25.c:477 __sys_listen_socket net/socket.c:2001 [inline] __sys_listen net/socket.c:2016 [inline] __do_sys_listen net/socket.c:2021 [inline] __se_sys_listen net/socket.c:2019 [inline] __x64_sys_listen+0x1c7/0x240 net/socket.c:2019 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 5252 hardirqs last enabled at (5252): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (5251): [] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455 softirqs last enabled at (5090): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last enabled at (5090): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last enabled at (5090): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 softirqs last disabled at (5133): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last disabled at (5133): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last disabled at (5133): [] __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.9.3610/18525: 5, last CPU#0: #0: ffff88802c5a0f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:586 [inline] #0: ffff88802c5a0f80 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302 #2: ffff888058f9ecd8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline] #2: ffff888058f9ecd8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:423 #3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: page_table_check_clear+0x1d0/0x590 mm/page_table_check.c:77 #4: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #4: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6357 stack backtrace: CPU: 0 UID: 0 PID: 18525 Comm: syz.9.3610 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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:1775 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6333 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6358 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7866 napi_poll net/core/dev.c:7929 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8086 handle_softirqs+0x223/0x840 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:rcu_lockdep_current_cpu_online+0xf4/0x120 kernel/rcu/tree.c:4234 Code: 00 4c 85 3b 75 1a 48 c7 c7 c0 0b d6 8e be 04 00 00 00 e8 7f 2f 8d 00 83 3d a8 df 28 0d 00 74 17 b0 01 65 48 ff 0d ec 03 e9 11 <74> 0f 5b 41 5e 41 5f c3 cc cc cc cc cc 31 c0 eb e7 e8 66 09 86 ff RSP: 0018:ffffc900049d72e8 EFLAGS: 00000282 RAX: 1ffffffff1dac001 RBX: ffffffff8ed60330 RCX: 8000000000000002 RDX: 0000000000000000 RSI: ffffffff8c6df660 RDI: ffff8880b863d1e8 RBP: 0000000000000001 R08: ffffffff82464620 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff940003037d1 R12: 00000000000606fa R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000001 rcu_read_lock_held_common kernel/rcu/update.c:114 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:350 lookup_page_ext mm/page_ext.c:253 [inline] page_ext_lookup+0xe7/0x180 mm/page_ext.c:504 page_ext_iter_begin include/linux/page_ext.h:136 [inline] page_table_check_clear+0x2a5/0x590 mm/page_table_check.c:78 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:1742 [inline] zap_present_ptes mm/memory.c:1824 [inline] do_zap_pte_range mm/memory.c:1926 [inline] zap_pte_range mm/memory.c:2028 [inline] zap_pmd_range mm/memory.c:2114 [inline] zap_pud_range mm/memory.c:2142 [inline] zap_p4d_range mm/memory.c:2163 [inline] __zap_vma_range+0x3a12/0x4f70 mm/memory.c:2203 unmap_vmas+0x38b/0x550 mm/memory.c:2272 exit_mmap+0x293/0x9f0 mm/mmap.c:1315 __mmput+0x118/0x420 kernel/fork.c:1192 exit_mm+0x18e/0x240 kernel/exit.c:586 do_exit+0x6a8/0x2380 kernel/exit.c:967 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 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: 0033:0x7f67df79e199 Code: Unable to access opcode bytes at 0x7f67df79e16f. RSP: 002b:00007f67e06a6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007f67dfa26090 RCX: 00007f67df79e199 RDX: 0000000000000010 RSI: 0000200000000300 RDI: 0000000000000004 RBP: 00007f67df8350b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f67dfa26128 R14: 00007f67dfa26090 R15: 00007fffefa69fa8 BUG: sleeping function called from invalid context at net/core/sock.c:3839 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 18525, name: syz.9.3610 preempt_count: 101, expected: 0 RCU nest depth: 3, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [<0000000000000000>] 0x0 CPU: 0 UID: 0 PID: 18525 Comm: syz.9.3610 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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:9197 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:1775 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6333 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6358 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7866 napi_poll net/core/dev.c:7929 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8086 handle_softirqs+0x223/0x840 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:rcu_lockdep_current_cpu_online+0xf4/0x120 kernel/rcu/tree.c:4234 Code: 00 4c 85 3b 75 1a 48 c7 c7 c0 0b d6 8e be 04 00 00 00 e8 7f 2f 8d 00 83 3d a8 df 28 0d 00 74 17 b0 01 65 48 ff 0d ec 03 e9 11 <74> 0f 5b 41 5e 41 5f c3 cc cc cc cc cc 31 c0 eb e7 e8 66 09 86 ff RSP: 0018:ffffc900049d72e8 EFLAGS: 00000282 RAX: 1ffffffff1dac001 RBX: ffffffff8ed60330 RCX: 8000000000000002 RDX: 0000000000000000 RSI: ffffffff8c6df660 RDI: ffff8880b863d1e8 RBP: 0000000000000001 R08: ffffffff82464620 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff940003037d1 R12: 00000000000606fa R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000001 rcu_read_lock_held_common kernel/rcu/update.c:114 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:350 lookup_page_ext mm/page_ext.c:253 [inline] page_ext_lookup+0xe7/0x180 mm/page_ext.c:504 page_ext_iter_begin include/linux/page_ext.h:136 [inline] page_table_check_clear+0x2a5/0x590 mm/page_table_check.c:78 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:1742 [inline] zap_present_ptes mm/memory.c:1824 [inline] do_zap_pte_range mm/memory.c:1926 [inline] zap_pte_range mm/memory.c:2028 [inline] zap_pmd_range mm/memory.c:2114 [inline] zap_pud_range mm/memory.c:2142 [inline] zap_p4d_range mm/memory.c:2163 [inline] __zap_vma_range+0x3a12/0x4f70 mm/memory.c:2203 unmap_vmas+0x38b/0x550 mm/memory.c:2272 exit_mmap+0x293/0x9f0 mm/mmap.c:1315 __mmput+0x118/0x420 kernel/fork.c:1192 exit_mm+0x18e/0x240 kernel/exit.c:586 do_exit+0x6a8/0x2380 kernel/exit.c:967 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 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: 0033:0x7f67df79e199 Code: Unable to access opcode bytes at 0x7f67df79e16f. RSP: 002b:00007f67e06a6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007f67dfa26090 RCX: 00007f67df79e199 RDX: 0000000000000010 RSI: 0000200000000300 RDI: 0000000000000004 RBP: 00007f67df8350b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f67dfa26128 R14: 00007f67dfa26090 R15: 00007fffefa69fa8 ---------------- Code disassembly (best guess): 0: 00 4c 85 3b add %cl,0x3b(%rbp,%rax,4) 4: 75 1a jne 0x20 6: 48 c7 c7 c0 0b d6 8e mov $0xffffffff8ed60bc0,%rdi d: be 04 00 00 00 mov $0x4,%esi 12: e8 7f 2f 8d 00 call 0x8d2f96 17: 83 3d a8 df 28 0d 00 cmpl $0x0,0xd28dfa8(%rip) # 0xd28dfc6 1e: 74 17 je 0x37 20: b0 01 mov $0x1,%al 22: 65 48 ff 0d ec 03 e9 decq %gs:0x11e903ec(%rip) # 0x11e90416 29: 11 * 2a: 74 0f je 0x3b <-- trapping instruction 2c: 5b pop %rbx 2d: 41 5e pop %r14 2f: 41 5f pop %r15 31: c3 ret 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: 31 c0 xor %eax,%eax 39: eb e7 jmp 0x22 3b: e8 66 09 86 ff call 0xff8609a6