rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=175385, q=9)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295044556-4295034054), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g175385 f0x2 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:27424 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/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 0
CPU: 0 PID: 20835 Comm: syz.2.4337 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x1110/0x1270 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+0x845/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 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:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:209
Code: 8b 15 05 73 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 <48> 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 16 00 00 48 39
RSP: 0000:ffffc90003f5fc50 EFLAGS: 00000246
RAX: ffffffff81ae881c RBX: ffff88801de7de50 RCX: ffff88801de7d940
RDX: 0000000000000002 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4200
RBP: 0000000000000023 R08: dffffc0000000000 R09: 1ffffffff203dc1e
R10: dffffc0000000000 R11: fffffbfff203dc1f R12: dffffc0000000000
R13: 00007f17adc469b8 R14: 1ffff11003bcfbca R15: 0000000000000000
 __might_fault+0xbc/0x110 mm/memory.c:5357
 _copy_to_user+0x29/0x130 lib/usercopy.c:35
 copy_to_user include/linux/uaccess.h:200 [inline]
 copy_siginfo_to_user+0x20/0x80 kernel/signal.c:3376
 __setup_rt_frame arch/x86/kernel/signal.c:490 [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+0xcf9/0x12a0 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
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f17af8a81b6
Code: 24 50 4c 8b 4c 24 58 4c 8b 6c 24 50 48 89 4c 24 30 48 8d 0d 9c d9 1a 00 48 29 ca 44 89 4c 24 24 49 8d bd 00 10 00 00 4c 89 e9 <49> c7 45 10 ff 03 00 00 49 89 7d 08 45 89 fd 4d 89 e7 49 89 cc 48
RSP: 002b:00007f17adc46f60 EFLAGS: 00010206
RAX: 0000000000000020 RBX: 0000000000000000 RCX: 00002000005cf000
RDX: 00000000000025f5 RSI: 00002000005cf000 RDI: 00002000005d0000
RBP: 00007f17afaa5600 R08: 0000000000000000 R09: ffffffffffffffff
R10: ffffffffffffffff R11: 0000000000000000 R12: 00000000003ff000
R13: 00002000005cf000 R14: 00007f17afc76fa0 R15: 0000000000000000
 </TASK>