rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=eb5/1/0x4000000000000000 softirq=39722/39727 fqs=4 
	(t=10500 jiffies g=51437 q=61)
rcu: rcu_preempt kthread starved for 10492 jiffies! g51437 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:28128 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729
NMI backtrace for cpu 0
CPU: 0 PID: 13622 Comm: syz.1.1831 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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+0x6d8/0x1110 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:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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+0x9b/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:__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: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 3e 1d aa f7 48 89 df e8 06 f2 aa f7 e8 81 8c cb f7 fb bf 01 00 00 00 <e8> 46 15 9f f7 65 8b 05 27 13 50 76 85 c0 74 02 5b c3 e8 d4 1d 4e
RSP: 0018:ffffc90003497bc0 EFLAGS: 00000282
RAX: 4fa368ccd88bf200 RBX: ffff88802a100000 RCX: 4fa368ccd88bf200
RDX: dffffc0000000000 RSI: ffffffff8a0b1620 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed1005420001
R10: ffffed1005420001 R11: 1ffff11005420000 R12: ffff88802a100000
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 get_signal+0x11d6/0x12c0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9a1bf18bab
Code: 24 1e 01 45 31 ff 45 31 f6 44 0f b6 e6 85 c0 0f 84 9e 00 00 00 44 89 f9 49 8b 50 40 4c 89 f0 49 03 14 ca 80 3d fd 91 36 00 00 <49> 89 d6 48 89 d5 74 28 25 ff 0f 00 00 83 f0 3d 8d 04 c0 89 c5 c1
RSP: 002b:00007ffc9a7bc610 EFLAGS: 00000202
RAX: ffffffff83a138dd RBX: 00007f9a1cdaf720 RCX: 0000000000000037
RDX: ffffffff83a18425 RSI: 00000000000004ff RDI: 0000000000000020
RBP: ffffffff83a13fed R08: 00007f9a1c280038 R09: 00007f9a1c26c000
R10: 00007f9a1baa9008 R11: 000000000000000a R12: 000000000000000a
R13: 0000000000000000 R14: ffffffff83a138dd R15: 0000000000000037
 </TASK>