syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=d6d/1/0x4000000000000000 softirq=69838/69839 fqs=3886 
	(t=10500 jiffies g=97929 q=1387)
NMI backtrace for cpu 0
CPU: 0 PID: 23136 Comm: syz.2.5127 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 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+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/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+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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+0x4ad/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 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_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 2c 98 f7 48 89 df e8 86 04 99 f7 e8 11 f3 b9 f7 fb bf 01 00 00 00 <e8> 06 0b 8d f7 65 8b 05 87 17 3d 76 85 c0 74 02 5b c3 e8 d4 24 3b
RSP: 0018:ffffc90000007c90 EFLAGS: 00000286
RAX: e9d9ed33a9a54a00 RBX: ffff8880b90280c0 RCX: e9d9ed33a9a54a00
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001
RBP: ffffc90000007df0 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: ffff8880b90280c0
R13: 1ffff11017205020 R14: ffff888060ee3410 R15: ffffc90000007d40
 expire_timers kernel/time/timer.c:1495 [inline]
 __run_timers+0x52b/0x7f0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x339/0x830 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_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
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 e5 2f 8e f7 e8 70 19 bb f7 fb bf 01 00 00 00 <e8> 65 b5 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9000350fda0 EFLAGS: 00000286
RAX: e9d9ed33a9a54a00 RBX: 0000000000000000 RCX: e9d9ed33a9a54a00
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001
RBP: ffffc9000350fe50 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920006a1fb4
 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 e2 a2 54 08 65 48 8b 05 ca 19 9b 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 ed 00 00 00 e8 35 f5 17 00 fb 41 f6 c6 08 <74> 05 e8 e9 d4 5c 08 41 f7 c6 00 10 00 00 74 08 48 89 df e8 58 60
RSP: 0018:ffffc9000350ff10 EFLAGS: 00000246
RAX: e9d9ed33a9a54a00 RBX: ffffc9000350ff58 RCX: e9d9ed33a9a54a00
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: 0000000000000000 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000004004 R15: ffff8880256b1dc0
 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_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0033:0x7fdc7d6b5084
Code: 5d 41 5c 41 5e c3 48 8b 44 24 20 48 8b 5c 24 08 48 8b b0 88 00 00 00 8b 78 08 48 8d 53 30 e8 13 3f ff ff 48 89 83 88 00 00 00 <e9> 35 fe ff ff 0f 1f 80 00 00 00 00 8b 7c 24 1c 48 8d 74 24 50 ba
RSP: 002b:00007fdc7ba29050 EFLAGS: 00000206
RAX: 000000000000001c RBX: 00007fdc7da6a090 RCX: 00007fdc7d85cbf7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007fdc7d85cbf7 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdc7da6a128 R14: 00007fdc7da6a090 R15: 00007ffc950ba458
 </TASK>