rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2651 jiffies s: 4145 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__lock_acquire+0x19cf/0x7d10 kernel/locking/lockdep.c:5053 Code: d8 00 00 00 42 80 3c 00 00 74 12 4c 89 ff e8 48 03 6f 00 49 b8 00 00 00 00 00 fc ff df 4d 89 37 48 8b 44 24 70 42 0f b6 04 00 <84> c0 0f 85 44 52 00 00 8b 03 ff c0 89 03 83 f8 30 0f 83 c5 40 00 RSP: 0018:ffffc900001dfc40 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff888017732898 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af5240 RBP: ffffc900001dfe90 R08: dffffc0000000000 R09: 1ffffffff215ea48 R10: dffffc0000000000 R11: fffffbfff215ea49 R12: d033492917843683 R13: 00000000632d906a R14: d033492917843683 R15: ffff888017732890 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb428e8b3e0 CR3: 000000002a671000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] pfn_valid include/linux/mmzone.h:1857 [inline] __virt_addr_valid+0x1a5/0x540 arch/x86/mm/physaddr.c:65 kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:36 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471 irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] trace_call_bpf+0x5bb/0x6b0 kernel/trace/bpf_trace.c:137 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable include/trace/events/preemptirq.h:40 [inline] trace_hardirqs_on_prepare+0x146/0x190 kernel/trace/trace_preemptirq.c:32 irqentry_exit+0x4b/0x70 kernel/entry/common.c:429 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 92 31 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001e04e0 EFLAGS: 00000206 RAX: 1f28b2b8bbbcd200 RBX: 1ffff9200003c0a4 RCX: 1f28b2b8bbbcd200 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0de0 RBP: ffffc900001e05d0 R08: ffffffff90af5307 R09: 1ffffffff215ea60 R10: dffffc0000000000 R11: fffffbfff215ea61 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] dev_queue_xmit_nit+0xa80/0xbb0 net/core/dev.c:2370 xmit_one net/core/dev.c:3679 [inline] dev_hard_start_xmit+0x154/0x870 net/core/dev.c:3699 sch_direct_xmit+0x25a/0x4b0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3920 [inline] __dev_queue_xmit+0x1771/0x37f0 net/core/dev.c:4325 lapb_data_transmit+0x86/0xa0 net/lapb/lapb_iface.c:447 lapb_transmit_buffer+0x15f/0x1f0 net/lapb/lapb_out.c:149 lapb_t1timer_expiry+0x652/0xa70 net/lapb/lapb_timer.c:-1 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 27 c3 9c f7 e9 44 ff ff ff e8 3d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 77 0c 50 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6 RAX: 1f28b2b8bbbcd200 RBX: ffffffff8a36a2b7 RCX: 1f28b2b8bbbcd200 RDX: 0000000000000001 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0de0 RBP: ffffc90000177f20 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 1ffff9200002efc8 R13: dffffc0000000000 R14: ffff888017731dc0 R15: 0000000000000001 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x20d/0x5a0 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xcf/0xdb INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.911 msecs