================================ WARNING: inconsistent lock state syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.2.4535/20890 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888025e84260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff888025e84260 (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_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:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 216348 hardirqs last enabled at (216348): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (216347): [] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455 softirqs last enabled at (214576): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last enabled at (214576): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last enabled at (214576): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 softirqs last disabled at (216265): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last disabled at (216265): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last disabled at (216265): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 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.2.4535/20890: 2, last CPU#0: #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 #1: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6269 stack backtrace: CPU: 0 UID: 0 PID: 20890 Comm: syz.2.4535 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: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+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:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 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:orc_find arch/x86/kernel/unwind_orc.c:228 [inline] RIP: 0010:unwind_next_frame+0x1f6/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: 08 8b 15 ed 9a da 0c 8d 42 ff 44 39 f8 0f 86 6c 04 00 00 44 89 f8 4c 8d 2c 85 b0 33 a0 91 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 <84> c0 4c 89 e3 0f 85 66 1d 00 00 45 8b 6d 00 44 89 f8 ff c0 4c 8d RSP: 0018:ffffc900062eee20 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 8000000000000000 RDX: 00000000000adfe9 RSI: ffffffff8c4c9460 RDI: ffffffff8c4c9420 RBP: ffffffff820be7a8 R08: 1300000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb5c8a0 R12: dffffc0000000000 R13: ffffffff91a4634c R14: ffffc900062eeec8 R15: 0000000000010be7 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:183 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] free_unref_folios+0xdc2/0x14e0 mm/page_alloc.c:3022 folios_put_refs+0x9e9/0xb30 mm/folio.c:1034 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1160 shmem_truncate_range mm/shmem.c:1288 [inline] shmem_evict_inode+0x247/0xae0 mm/shmem.c:1419 evict+0x624/0xb50 fs/inode.c:822 dentry_kill+0x1b9/0x880 fs/dcache.c:826 finish_dput+0x1a/0x260 fs/dcache.c:1001 __fput+0x675/0xa50 fs/file_table.c:520 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1008 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 kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x2ba/0x910 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fecb939e0e1 Code: Unable to access opcode bytes at 0x7fecb939e0b7. RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fecb9625fa0 RCX: 00007fecb939e0d9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fecb9435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fecb9626038 R14: 00007fecb9625fa0 R15: 00007fff7a390d58 BUG: sleeping function called from invalid context at net/core/sock.c:3829 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 20890, name: syz.2.4535 preempt_count: 100, expected: 0 RCU nest depth: 2, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [] softirq_handle_begin kernel/softirq.c:486 [inline] [] handle_softirqs+0xab/0x860 kernel/softirq.c:621 CPU: 0 UID: 0 PID: 20890 Comm: syz.2.4535 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:9203 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+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:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 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:orc_find arch/x86/kernel/unwind_orc.c:228 [inline] RIP: 0010:unwind_next_frame+0x1f6/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: 08 8b 15 ed 9a da 0c 8d 42 ff 44 39 f8 0f 86 6c 04 00 00 44 89 f8 4c 8d 2c 85 b0 33 a0 91 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 <84> c0 4c 89 e3 0f 85 66 1d 00 00 45 8b 6d 00 44 89 f8 ff c0 4c 8d RSP: 0018:ffffc900062eee20 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 8000000000000000 RDX: 00000000000adfe9 RSI: ffffffff8c4c9460 RDI: ffffffff8c4c9420 RBP: ffffffff820be7a8 R08: 1300000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb5c8a0 R12: dffffc0000000000 R13: ffffffff91a4634c R14: ffffc900062eeec8 R15: 0000000000010be7 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:183 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] free_unref_folios+0xdc2/0x14e0 mm/page_alloc.c:3022 folios_put_refs+0x9e9/0xb30 mm/folio.c:1034 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1160 shmem_truncate_range mm/shmem.c:1288 [inline] shmem_evict_inode+0x247/0xae0 mm/shmem.c:1419 evict+0x624/0xb50 fs/inode.c:822 dentry_kill+0x1b9/0x880 fs/dcache.c:826 finish_dput+0x1a/0x260 fs/dcache.c:1001 __fput+0x675/0xa50 fs/file_table.c:520 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1008 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 kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x2ba/0x910 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fecb939e0e1 Code: Unable to access opcode bytes at 0x7fecb939e0b7. RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fecb9625fa0 RCX: 00007fecb939e0d9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fecb9435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fecb9626038 R14: 00007fecb9625fa0 R15: 00007fff7a390d58 ---------------- Code disassembly (best guess): 0: 08 8b 15 ed 9a da or %cl,-0x256512eb(%rbx) 6: 0c 8d or $0x8d,%al 8: 42 ff 44 39 f8 incl -0x8(%rcx,%r15,1) d: 0f 86 6c 04 00 00 jbe 0x47f 13: 44 89 f8 mov %r15d,%eax 16: 4c 8d 2c 85 b0 33 a0 lea -0x6e5fcc50(,%rax,4),%r13 1d: 91 1e: 4c 89 e8 mov %r13,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax * 2a: 84 c0 test %al,%al <-- trapping instruction 2c: 4c 89 e3 mov %r12,%rbx 2f: 0f 85 66 1d 00 00 jne 0x1d9b 35: 45 8b 6d 00 mov 0x0(%r13),%r13d 39: 44 89 f8 mov %r15d,%eax 3c: ff c0 inc %eax 3e: 4c rex.WR 3f: 8d .byte 0x8d