rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=1f3/1/0x4000000000000000 softirq=26158/26159 fqs=324 
	(t=10500 jiffies g=33185 q=261)
rcu: rcu_preempt kthread starved for 9848 jiffies! g33185 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:26752 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 schedule+0x11b/0x1f0 kernel/sched/core.c:6458
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 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 acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562
NMI backtrace for cpu 1
CPU: 1 PID: 8138 Comm: syz.4.525 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 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:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x16c/0x1f0 kernel/softirq.c:390
Code: 8a e8 38 67 f2 08 65 66 8b 05 d0 eb b5 7e 66 85 c0 75 57 bf 01 00 00 00 e8 51 f2 09 00 e8 3c 6e 39 00 fb 65 8b 05 bc c2 b4 7e <85> c0 75 05 e8 8b df b2 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c
RSP: 0018:ffffc90002def9e0 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 1ffff920005bdf40 RCX: ffffffff96a95f03
RDX: dffffc0000000000 RSI: ffffffff8aab2a60 RDI: ffffffff8af9fa80
RBP: ffffc90002defa90 R08: ffffffff81871b70 R09: ffffed1027fe3e41
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff920005bdf44 R14: ffffc90002defa20 R15: 0000000000000200
 fpregs_unlock arch/x86/include/asm/fpu/api.h:78 [inline]
 restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:300 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
 fpu__restore_sig+0x841/0x1100 arch/x86/kernel/fpu/signal.c:466
 restore_sigcontext+0x638/0x710 arch/x86/kernel/signal.c:139
 __do_sys_rt_sigreturn+0x190/0x250 arch/x86/kernel/signal.c:674
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f05a3913167
Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007f05a177c038 EFLAGS: 00000246
RAX: 0000000000000113 RBX: 00007f05a3b2bfa0 RCX: 00007f05a3913169
RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f05a39942a0 R08: 0000000008000f28 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f05a3b2bfa0 R15: 00007ffdef726238
 </TASK>