rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2666 jiffies s: 2217 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:234 Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 44 fa 7f 7e 65 8b RSP: 0018:ffffc90000006fd8 EFLAGS: 00000046 RAX: ffffffff813a104b RBX: 00000000b8e3b9f0 RCX: ffffffff8c8bc740 RDX: 0000000000000100 RSI: ffffffff8adf0d00 RDI: ffffffff8adf0cc0 RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff215ee48 R10: dffffc0000000000 R11: fffffbfff215ee49 R12: dffffc0000000000 R13: dffffc0000000001 R14: ffffffff813a1008 R15: ffff88813fff92e0 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555590540328 CR3: 0000000074b1c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_sched include/linux/rcupdate.h:884 [inline] pfn_valid include/linux/mmzone.h:1857 [inline] __virt_addr_valid+0x1cb/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:10027 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 d2 33 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:ffffc900000074e0 EFLAGS: 00000206 RAX: 935a965bd9839d00 RBX: 1ffff92000000ea4 RCX: 935a965bd9839d00 RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20 RBP: ffffc900000075d0 R08: ffffffff90af7307 R09: 1ffffffff215ee60 R10: dffffc0000000000 R11: fffffbfff215ee61 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8e3b900 R15: 0000000000000001 __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+0x1771/0x37c0 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 47 c2 9b 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 57 eb 4e 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:ffffffff8c807d88 EFLAGS: 000002c6 RAX: 935a965bd9839d00 RBX: ffffffff8a37c257 RCX: 935a965bd9839d00 RDX: 0000000000000001 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20 RBP: ffffffff8c807ec0 R08: ffff8880b8e3580b R09: 1ffff110171c6b01 R10: dffffc0000000000 R11: ffffed10171c6b02 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8c8bc740 R15: 1ffffffff1900fbc default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a2/0x680 kernel/sched/idle.c:323 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422 rest_init+0x2dc/0x300 init/main.c:745 arch_call_rest_init+0xa/0xa init/main.c:905 start_kernel+0x493/0x53c init/main.c:1152 secondary_startup_64_no_verify+0xcf/0xdb INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.928 msecs