rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10500 ticks this GP) idle=e89/1/0x4000000000000000 softirq=12008/12008 fqs=764
(t=10502 jiffies g=14585 q=582)
rcu: rcu_preempt kthread starved for 8974 jiffies! g14585 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:28016 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:1914
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: 5365 Comm: syz.0.224 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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: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+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:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:408
Code: 8a e8 16 0c 71 08 65 66 8b 05 8e 6a ba 7e 66 85 c0 75 54 bf 01 00 00 00 e8 bf 24 09 00 e8 6a 0d 36 00 fb 65 8b 05 3a 41 b9 7e <85> c0 75 05 e8 89 4e b7 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc90005b9fc20 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000200 RCX: d3f07d26c0642600
RDX: dffffc0000000000 RSI: ffffffff8a2b1c00 RDI: ffffffff8a79e740
RBP: ffffc90005b9fcb0 R08: ffff88813fe1f207 R09: 1ffff11027fc3e40
R10: dffffc0000000000 R11: ffffed1027fc3e41 R12: ffffffff812c09f5
R13: 1ffff92000b73fff R14: dffffc0000000000 R15: 1ffff92000b73f84
handle_signal arch/x86/kernel/signal.c:840 [inline]
arch_do_signal_or_restart+0xec1/0x12c0 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: 0033:0x7f6afcc90250
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d c2 1f 09 00 e8 e5 65 f9 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007fff96aa3138 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff817f4e6b RCX: ffffffff817f4e6b
RDX: 00007fff96aa3140 RSI: 00007fff96aa3270 RDI: 0000000000000021
RBP: 0000000000000286 R08: 00007f6afced6000 R09: 00007f6afced8000
R10: 00000000817f4e6f R11: 000000000000000c R12: 00007f6afceec038
R13: 000000000007cf8e R14: ffffffff817f406a R15: 00007f6afda1b720
sched: RT throttling activated