rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (0 ticks this GP) idle=affc/1/0x4000000000000000 softirq=19902/19902 fqs=3
rcu: (detected by 0, t=10502 jiffies, g=75045, q=679 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11768 Comm: syz.5.2292 Tainted: G L syzkaller #0 PREEMPT(lazy)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:__lock_release kernel/locking/lockdep.c:5546 [inline]
RIP: 0010:lock_release+0x140/0x3c0 kernel/locking/lockdep.c:5889
Code: 0f 84 d7 00 00 00 48 85 ed 0f 84 13 01 00 00 83 7d 24 00 0f 85 d6 01 00 00 8b 45 20 3d 00 00 20 00 48 8b 5c 24 08 8b 54 24 14 <72> 25 89 c1 81 e1 00 00 e0 ff 25 ff ff 1f 00 01 c8 05 00 00 e0 ff
RSP: 0018:ffffc90000a08ca0 EFLAGS: 00000087
RAX: 00000000000c4000 RBX: 0000000000000002 RCX: 0000000080010002
RDX: 0000000000000001 RSI: ffffffff9a9eb228 RDI: ffff8880279b0bc8
RBP: ffff8880279b0bc8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141190 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff9a9eb228 R15: ffff8880279b0000
FS: 0000000000000000(0000) GS:ffff888125055000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3371dff8 CR3: 0000000071d01000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:198
debug_object_activate+0x2ec/0x420 lib/debugobjects.c:891
debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline]
debug_activate kernel/time/hrtimer.c:528 [inline]
enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1109
__run_hrtimer kernel/time/hrtimer.c:2048 [inline]
__hrtimer_run_queues+0x4ce/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:stack_not_used kernel/exit.c:833 [inline]
RIP: 0010:check_stack_usage kernel/exit.c:882 [inline]
RIP: 0010:do_exit+0x192b/0x2360 kernel/exit.c:1044
Code: f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 05 e8 95 bc ac 00 49 83 3c 1f 00 75 0f e8 59 20 3f 00 48 83 c3 08 <49> 83 c6 f8 eb ca bf 01 04 00 00 4c 89 f6 e8 22 25 3f 00 49 81 fe
RSP: 0018:ffffc9000e37fd40 EFLAGS: 00000206
RAX: ffffffff8187e107 RBX: 00000000000047d8 RCX: ffff8880279b0000
RDX: 0000000000000000 RSI: ffffffff8e4adf3a RDI: ffffc9000e37c7d0
RBP: ffffc9000e37fe80 R08: ffffffff823dde19 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffff888035f28750
R13: 1ffff11004f360bb R14: 0000000000003830 R15: ffffc9000e378000
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
__do_sys_exit_group kernel/exit.c:1163 [inline]
__se_sys_exit_group kernel/exit.c:1161 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8bd919e0d9
Code: Unable to access opcode bytes at 0x7f8bd919e0af.
RSP: 002b:00007ffd4c0aa4c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8bd919e0d9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd4c0aa52c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000181
R13: 00000000000927c0 R14: 0000000000063dd3 R15: 00007ffd4c0aa580
rcu: rcu_preempt kthread starved for 10496 jiffies! g75045 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:27736 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 37 Comm: kworker/u8:2 Tainted: G L syzkaller #0 PREEMPT(lazy)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x11eb/0x15f0 kernel/smp.c:912
Code: 1e 89 de 83 e6 01 31 ff e8 e2 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1a 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 73 1a 0c 00 eb e5 44 89
RSP: 0018:ffffc90000ad7700 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff8880206a1f00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000ad7860 R08: ffffffff90574837 R09: 1ffffffff20ae906
R10: dffffc0000000000 R11: fffffbfff20ae907 R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124f55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3360cff8 CR3: 000000000e946000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:911
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245