rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=45f/1/0x4000000000000000 softirq=6790/6791 fqs=324 
	(t=10500 jiffies g=7521 q=468)
rcu: rcu_preempt kthread starved for 9845 jiffies! g7521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27008 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 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 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:728
NMI backtrace for cpu 1
CPU: 1 PID: 4437 Comm: syz.0.34 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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 7e db aa f7 48 89 df e8 46 b0 ab f7 e8 91 46 cc f7 fb bf 01 00 00 00 <e8> 76 d4 9f f7 65 8b 05 17 d4 50 76 85 c0 74 02 5b c3 e8 c4 de 4e
RSP: 0018:ffffc90002f0fb50 EFLAGS: 00000282
RAX: 3dc0d0347e902e00 RBX: ffff88802a371bc0 RCX: 3dc0d0347e902e00
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001
RBP: ffffc90002f0fcb0 R08: dffffc0000000000 R09: ffffed100546e379
R10: ffffed100546e379 R11: 1ffff1100546e378 R12: dffffc0000000000
R13: 0000000000010000 R14: 0000000000000000 R15: 0000000000000010
 set_current_blocked kernel/signal.c:3072 [inline]
 signal_delivered kernel/signal.c:2936 [inline]
 signal_setup_done+0x28c/0x440 kernel/signal.c:2947
 handle_signal arch/x86/kernel/signal.c:842 [inline]
 arch_do_signal_or_restart+0xf2e/0x1300 arch/x86/kernel/signal.c:869
 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: 0033:0x7f55c8158980
Code: 44 24 20 0f 29 44 24 30 0f 29 44 24 40 48 8b 44 24 08 ff d0 48 83 c4 50 31 c0 5b 5d 41 5c 41 5d 41 5e c3 0f 1f 80 00 00 00 00 <c3> 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 c3 66 66 2e 0f 1f
RSP: 002b:00007f55c6100b38 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f55c84c0fa8 RCX: 00007f55c82999a9
RDX: 00007f55c6100b40 RSI: 00007f55c6100c70 RDI: 0000000000000011
RBP: 00007f55c84c0fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f55c84c0fac
R13: 0000000000000000 R14: 00007ffd9f02c670 R15: 00007ffd9f02c758
 </TASK>