================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.4.676/8882 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88806862c260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff88806862c260 (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:5908 lock_sock_nested+0x41/0x100 net/core/sock.c:3827 lock_sock include/net/sock.h:1713 [inline] x25_bind+0x209/0x450 net/x25/af_x25.c:694 __sys_bind_socket net/socket.c:1945 [inline] __sys_bind+0x2e3/0x410 net/socket.c:1976 __do_sys_bind net/socket.c:1981 [inline] __se_sys_bind net/socket.c:1979 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1979 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 1948 hardirqs last enabled at (1948): [] __local_bh_enable_ip+0xd0/0x130 kernel/softirq.c:457 hardirqs last disabled at (1947): [] __local_bh_enable_ip+0x71/0x130 kernel/softirq.c:434 softirqs last enabled at (1778): [] __do_softirq kernel/softirq.c:658 [inline] softirqs last enabled at (1778): [] invoke_softirq kernel/softirq.c:498 [inline] softirqs last enabled at (1778): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 softirqs last disabled at (1781): [] __do_softirq kernel/softirq.c:658 [inline] softirqs last disabled at (1781): [] invoke_softirq kernel/softirq.c:498 [inline] softirqs last disabled at (1781): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 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.4.676/8882: 5, last CPU#0: #0: ffff88802bfbb6b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff88802bfbb6b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290 #2: ffff888026d33cd8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] #2: ffff888026d33cd8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 #3: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: page_table_check_clear+0x124/0x500 mm/page_table_check.c:77 #4: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #4: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6269 stack backtrace: CPU: 0 UID: 0 PID: 8882 Comm: syz.4.676 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+0x28b/0x2e0 kernel/locking/lockdep.c:4058 valid_state+0xbe/0xf0 kernel/locking/lockdep.c:4072 mark_lock_irq+0x36/0x380 kernel/locking/lockdep.c:4283 mark_lock+0x117/0x190 kernel/locking/lockdep.c:4769 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x6b7/0x2e50 kernel/locking/lockdep.c:5208 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 lock_sock_nested+0x41/0x100 net/core/sock.c:3827 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:6245 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6270 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7768 napi_poll net/core/dev.c:7831 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7988 handle_softirqs+0x225/0x840 kernel/softirq.c:624 __do_softirq kernel/softirq.c:658 [inline] invoke_softirq kernel/softirq.c:498 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 irq_exit_rcu+0x9/0x30 kernel/softirq.c:754 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:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5987 Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 6c 7e 96 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc900049af2e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8e4dae69 RDI: ffffffff8c4c8980 RBP: 00000000ffffffff R08: d600000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb5c820 R12: 0000000000000246 R13: ffff888032958000 R14: ffffffff8eb5c820 R15: 0000000000000001 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+0x212/0x500 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: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:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 get_signal+0x121b/0x12c0 kernel/signal.c:3039 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+0x104/0x750 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:336 [inline] do_syscall_64+0x328/0x510 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f71a119e0d9 Code: Unable to access opcode bytes at 0x7f71a119e0af. RSP: 002b:00007f71a20610e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f71a1426098 RCX: 00007f71a119e0d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f71a1426098 RBP: 00007f71a1426090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f71a1426128 R14: 00007ffc0fb18160 R15: 00007ffc0fb18248 BUG: sleeping function called from invalid context at net/core/sock.c:3829 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 8882, name: syz.4.676 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: 8882 Comm: syz.4.676 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+0x378/0x4d0 kernel/sched/core.c:9195 lock_sock_nested+0x56/0x100 net/core/sock.c:3829 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:6245 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6270 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7768 napi_poll net/core/dev.c:7831 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7988 handle_softirqs+0x225/0x840 kernel/softirq.c:624 __do_softirq kernel/softirq.c:658 [inline] invoke_softirq kernel/softirq.c:498 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 irq_exit_rcu+0x9/0x30 kernel/softirq.c:754 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:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5987 Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 6c 7e 96 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc900049af2e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8e4dae69 RDI: ffffffff8c4c8980 RBP: 00000000ffffffff R08: d600000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb5c820 R12: 0000000000000246 R13: ffff888032958000 R14: ffffffff8eb5c820 R15: 0000000000000001 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+0x212/0x500 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: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:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 get_signal+0x121b/0x12c0 kernel/signal.c:3039 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+0x104/0x750 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:336 [inline] do_syscall_64+0x328/0x510 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f71a119e0d9 Code: Unable to access opcode bytes at 0x7f71a119e0af. RSP: 002b:00007f71a20610e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f71a1426098 RCX: 00007f71a119e0d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f71a1426098 RBP: 00007f71a1426090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f71a1426128 R14: 00007ffc0fb18160 R15: 00007ffc0fb18248 ---------------- Code disassembly (best guess): 0: 1b 00 sbb (%rax),%eax 2: 00 b8 ff ff ff ff add %bh,-0x1(%rax) 8: 65 0f c1 05 6c 7e 96 xadd %eax,%gs:0x7967e6c(%rip) # 0x7967e7c f: 07 10: 83 f8 01 cmp $0x1,%eax 13: 75 25 jne 0x3a 15: 9c pushf 16: 58 pop %rax 17: a9 00 02 00 00 test $0x200,%eax 1c: 75 39 jne 0x57 1e: 41 f7 c4 00 02 00 00 test $0x200,%r12d 25: 74 01 je 0x28 27: fb sti 28: 89 d8 mov %ebx,%eax * 2a: 5b pop %rbx <-- trapping instruction 2b: 41 5c pop %r12 2d: 41 5d pop %r13 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: 5d pop %rbp 34: c3 ret 35: cc int3 36: cc int3 37: cc int3 38: cc int3 39: cc int3 3a: 90 nop 3b: 0f 0b ud2 3d: 90 nop 3e: 48 rex.W 3f: c7 .byte 0xc7