rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2692 jiffies s: 2013 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: 4690 Comm: syz.2.91 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:unwind_next_frame+0x9e0/0x20b0 arch/x86/include/asm/stacktrace.h:-1 Code: 10 4d 89 fd 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 4c 89 ff e8 e8 5e 9a 00 4c 89 bc 24 90 00 00 00 <48> 8b 04 24 48 8d 68 f8 4c 8b 7b 10 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000006e48 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffc90000006fe0 RCX: ffffffff8e34d8e0 RDX: ffffc90000007500 RSI: ffffffff8e34d8dc RDI: 0000000000000001 RBP: ffffffff8ea728a6 R08: 0000000000000001 R09: ffffc90000007030 R10: dffffc0000000000 R11: fffff52000000e08 R12: 1ffff92000000dfd R13: 1ffff92000000dfe R14: ffffc90000000000 R15: ffffc90000006ff0 FS: 00007f8bd59406c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 00000000253f6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:717 unwind_start arch/x86/include/asm/unwind.h:64 [inline] perf_callchain_kernel+0x29e/0x680 arch/x86/events/core.c:-1 get_perf_callchain+0x236/0x490 kernel/events/callchain.c:204 perf_callchain kernel/events/core.c:7512 [inline] perf_prepare_sample+0x399/0x2020 kernel/events/core.c:7545 __perf_event_output kernel/events/core.c:7730 [inline] perf_event_output_forward+0x197/0x2f0 kernel/events/core.c:7750 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496 perf_swevent_overflow kernel/events/core.c:9579 [inline] perf_swevent_event+0x315/0x570 kernel/events/core.c:9630 perf_tp_event+0x3e7/0xc30 kernel/events/core.c:10064 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 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 82 22 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:ffffc900000079c0 EFLAGS: 00000206 RAX: c09f6ea15d8e0a00 RBX: 1ffff92000000f40 RCX: c09f6ea15d8e0a00 RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: ffffffff8adf1b60 RBP: ffffc90000007ac0 R08: ffff8880b8e3580b R09: 1ffff110171c6b01 R10: dffffc0000000000 R11: ffffed10171c6b02 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] process_backlog+0x410/0x6f0 net/core/dev.c:6062 __napi_poll+0xc0/0x460 net/core/dev.c:6628 napi_poll net/core/dev.c:6695 [inline] net_rx_action+0x5dd/0xb20 net/core/dev.c:6809 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:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5124 Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 a0 eb de 08 e8 5b 2d 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc9000bf7f8f8 EFLAGS: 00000282 RAX: c09f6ea15d8e0a00 RBX: 0000000000000000 RCX: c09f6ea15d8e0a00 RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: ffffffff8adf1b60 RBP: ffffc9000bf7f950 R08: ffff8880b8e3580b R09: 1ffff110171c6b01 R10: dffffc0000000000 R11: ffffed10171c6b02 R12: ffff88807e2e8000 R13: dffffc0000000000 R14: ffff88807e6e5940 R15: ffff8880b8e3b5d0 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x11d9/0x40e0 kernel/sched/core.c:6562 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] futex_wake+0x419/0x4f0 kernel/futex/waitwake.c:183 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8bd499ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8bd59400e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f8bd4c15fa8 RCX: 00007f8bd499ce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f8bd4c15fac RBP: 00007f8bd4c15fa0 R08: 0002c438cfc3b05a R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8bd4c16038 R14: 00007ffe1df87450 R15: 00007ffe1df87538