rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10499 ticks this GP) idle=1b9/1/0x4000000000000000 softirq=6509/6518 fqs=24
(t=10500 jiffies g=6937 q=870)
rcu: rcu_preempt kthread starved for 10451 jiffies! g6937 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
CPU: 0 PID: 4382 Comm: syz.3.20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline]
RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 df 42 d0 02 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000007e48 EFLAGS: 00000046
RAX: 000000000007d758 RBX: 000000000007d758 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000007d758 RDI: 0000000000000838
RBP: 0000000000000000 R08: ffffffff8d8956ef R09: 1ffffffff1b12add
R10: dffffc0000000000 R11: fffffbfff1b12ade R12: dffffc0000000000
R13: 00000000100062fc R14: ffffffff8be279d8 R15: dffffc0000000000
FS: 0000555584b24500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000725ba000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
apic_write arch/x86/include/asm/apic.h:395 [inline]
lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468
clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334
hrtimer_interrupt+0x4de/0x8d0 kernel/time/hrtimer.c:1824
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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 2e de 99 f7 48 89 df e8 66 b6 9a f7 e8 f1 a4 bb f7 fb bf 01 00 00 00 36 bc 8e f7 65 8b 05 b7 d8 3e 76 85 c0 74 02 5b c3 e8 04 e6 3c
RSP: 0018:ffffc9000318fbc0 EFLAGS: 00000282
RAX: a463c0f8074c4b00 RBX: ffff88807c678000 RCX: a463c0f8074c4b00
RDX: dffffc0000000000 RSI: ffffffff8a2b1c00 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88807c678003 R09: 1ffff1100f8cf000
R10: dffffc0000000000 R11: ffffed100f8cf001 R12: ffff88807c678000
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
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: 0033:0x7faa3e4cfcb9
Code: 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 01 48
RSP: 002b:00007ffedab90948 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007faa3e4cfcb9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007faa3e74afac
RBP: 0000000000001db5 R08: 001352188ae62b68 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faa3e74afac R14: 00007faa3e74afa8 R15: 00007faa3e74afa0
NMI backtrace for cpu 1
sched: RT throttling activated
CPU: 1 PID: 4381 Comm: syz.1.18 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+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0033:0x7f0ecacc2ad7
Code: 8d 3d 5b 4a 0b 00 e8 58 1d fa ff e8 23 87 00 00 0f 1f 00 b8 68 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007ffce725a608 EFLAGS: 00000202
RAX: 0000000000000003 RBX: 00007ffce725a770 RCX: 00007f0ecacc2ad7
RDX: 00007ffce725a640 RSI: 00007ffce725a770 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f0ecaf43fac R14: 00007f0ecaf43fa0 R15: 00007f0ecaf43fa0