rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=8937, q=402)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294959248-4294948745), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g8937 f0x2 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:27584 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:
NMI backtrace for cpu 1
CPU: 1 PID: 4457 Comm: syz.4.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 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:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 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+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:xsave_to_user_sigframe arch/x86/include/asm/fpu/internal.h:351 [inline]
RIP: 0010:copy_fpregs_to_sigframe arch/x86/kernel/fpu/signal.c:141 [inline]
RIP: 0010:copy_fpstate_to_sigframe+0x47e/0xb90 arch/x86/kernel/fpu/signal.c:203
Code: 49 89 c7 48 89 c6 41 be ff ff ff ff 4c 21 f6 31 ff e8 06 09 4c 00 4d 21 f7 75 4a e8 1c 05 4c 00 41 81 e4 ff 02 00 00 0f 01 cb <48> 89 df 44 89 e0 31 d2 48 0f ae 27 31 c0 41 89 c4 0f 01 ca 4c 8b
RSP: 0018:ffffc9000417fb20 EFLAGS: 00040202
RAX: ffffffff812bc534 RBX: 00007ffdf2002a80 RCX: ffff888027fd0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000417fcb0 R08: dffffc0000000000 R09: ffffed1004ffa001
R10: ffffed1004ffa001 R11: 1ffff11004ffa000 R12: 0000000000000007
R13: ffff888027fd1788 R14: 00000000ffffffff R15: 0000000000000000
 get_sigframe arch/x86/kernel/signal.c:295 [inline]
 __setup_rt_frame arch/x86/kernel/signal.c:471 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
 handle_signal arch/x86/kernel/signal.c:824 [inline]
 arch_do_signal_or_restart+0x67a/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+0xee/0x180 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: 0033:0x7ffdf21a2914
Code: ff 81 3d 8f b7 ff ff ff ff ff 7f 48 8d 0d 84 e7 ff ff 48 0f 45 c8 48 8b 41 20 48 85 ff 74 03 48 89 07 5d c3 66 90 55 48 89 e5 <41> 57 41 56 41 55 41 54 53 48 83 ec 18 83 ff 0f 0f 87 57 01 00 00
RSP: 002b:00007ffdf2002e70 EFLAGS: 00000202
RAX: 00007ffdf21a2910 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00007f7017fd2120 RSI: 00007ffdf2002ee0 RDI: 0000000000000001
RBP: 00007ffdf2002e70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f701811cfa0 R14: 00007f701811cfa0 R15: 0000000000000004
 </TASK>