rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=76d/1/0x4000000000000000 softirq=96353/96354 fqs=2042 (t=10500 jiffies g=115737 q=2027) NMI backtrace for cpu 1 CPU: 1 PID: 29771 Comm: syz.1.6639 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 ef bf 89 f7 65 8b 05 00 e7 39 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0000:ffffc90000dd0a40 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 660eef7d61d11500 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001 RBP: ffffc90000dd0ad8 R08: ffffffff901e91b7 R09: 1ffffffff203d236 R10: dffffc0000000000 R11: fffffbfff203d237 R12: dffffc0000000000 R13: ffff8880b91280c0 R14: ffff8880b91280c0 R15: 1ffff920001ba148 __mod_timer+0x925/0xd20 kernel/time/timer.c:1081 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x56c/0x810 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x336/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9d/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6799 Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 7f bf 01 00 00 00 e8 75 e5 8a f7 e8 20 b7 b7 f7 fb bf 01 00 00 00 d5 b5 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f RSP: 0000:ffffc900032cfda0 EFLAGS: 00000286 RAX: 660eef7d61d11500 RBX: 0000000000000000 RCX: 660eef7d61d11500 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001 RBP: ffffc900032cfe50 R08: ffffffff8f0fe048 R09: ffffffff8f0fe058 R10: ffffffff8f0fe050 R11: ffffffff8f0fe043 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000659fb4 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:exit_to_user_mode_loop+0x40/0x130 kernel/entry/common.c:168 Code: fb eb 1d e8 52 04 58 08 65 48 8b 05 8a 4d 9b 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 ed 00 00 00 e8 85 f6 17 00 fb 41 f6 c6 08 <74> 05 e8 89 38 60 08 41 f7 c6 00 10 00 00 74 08 48 89 df e8 98 67 RSP: 0000:ffffc900032cff10 EFLAGS: 00000246 RAX: 660eef7d61d11500 RBX: ffffc900032cff58 RCX: 660eef7d61d11500 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a2a40 RBP: 0000000000000000 R08: ffffffff8f0fe048 R09: ffffffff8f0fe058 R10: ffffffff8f0fe050 R11: ffffffff8f0fe043 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000004 R15: ffff888027888000 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0033:0x7fb376a41e59 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:00007fb374c9a028 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fb376cc9fa0 RCX: 00007fb376a41e59 RDX: 0000000000000006 RSI: 0000000040042408 RDI: 0000000000000005 RBP: 00007fb376ad7e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb376cca038 R14: 00007fb376cc9fa0 R15: 00007ffc10d5eee8