rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10500 ticks this GP) idle=7eb/1/0x4000000000000000 softirq=32303/32303 fqs=490
(t=10502 jiffies g=41485 q=143)
rcu: rcu_preempt kthread starved for 9523 jiffies! g41485 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:26544 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 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/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
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:729
NMI backtrace for cpu 1
CPU: 1 PID: 10353 Comm: syz.4.1260 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
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_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+0x6ea/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+0x4ad/0xb70 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
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:fpu__restore_sig+0x2fe/0x1060 arch/x86/kernel/fpu/signal.c:473
Code: f8 66 43 c7 44 27 10 f8 f8 e8 5e cc ff ff 89 d8 48 c7 44 24 60 0e 36 e0 45 4b c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 <4b> c7 44 27 10 00 00 00 00 4b c7 44 27 18 00 00 00 00 65 48 8b 0c
RSP: 0018:ffffc90003d3fb40 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff1100fcdae19 RCX: 105fc9aa2afef600
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f740
RBP: ffffc90003d3fcf0 R08: ffff88813fe23207 R09: 1ffff11027fc4640
R10: dffffc0000000000 R11: ffffed1027fc4641 R12: dffffc0000000000
R13: ffff88807e6d5940 R14: f8f8f8f8f8f8f8f8 R15: 1ffff920007a7f74
restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
__ia32_sys_rt_sigreturn+0x5e4/0x760 arch/x86/kernel/signal.c:674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6b84fc8627
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f6b83222028 EFLAGS: 00000246
RAX: 0000000000000048 RBX: 00007f6b85241fa0 RCX: 00007f6b84fc8629
RDX: 0000200000000280 RSI: 0000000000000026 RDI: 0000000000000003
RBP: 00007f6b8505eb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6b85242038 R14: 00007f6b85241fa0 R15: 00007fff80341b98