rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=9354/1/0x4000000000000000 softirq=47029/47029 fqs=4
rcu: 	(detected by 1, t=10506 jiffies, g=29949, q=1148 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5645 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:lock_acquire+0x224/0x350 kernel/locking/lockdep.c:5872
Code: e8 51 f4 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 3b 7f 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 5b 41 5c <41> 5d 41 5e 41 5f 5d e9 0b 90 6e ff cc 48 8d 3d c8 5a 92 0e 67 48
RSP: 0018:ffffc90000007cd0 EFLAGS: 00000086
RAX: 788bd2dd2fa7e900 RBX: ffff888079a822a8 RCX: 0000000000010003
RDX: 0000000022209f00 RSI: ffffffff8e219861 RDI: ffffffff8c28ade0
RBP: ffffffff89b853e4 R08: ffffffff89b853e4 R09: ffff888079a822c0
R10: dffffc0000000000 R11: ffffffff89b85330 R12: ffff88802c2467b8
R13: ffff888079a822c0 R14: 0000000000000001 R15: 0000000000000046
FS:  00005555796ab500(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31623ffc CR3: 000000005aa69000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
 spin_lock include/linux/spinlock.h:342 [inline]
 advance_sched+0xb4/0xc20 net/sched/sch_taprio.c:930
 __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
 __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:is_zero_page include/linux/mm.h:2670 [inline]
RIP: 0010:is_zero_folio include/linux/mm.h:2681 [inline]
RIP: 0010:__folio_rmap_sanity_checks include/linux/rmap.h:338 [inline]
RIP: 0010:__folio_dup_file_rmap include/linux/rmap.h:498 [inline]
RIP: 0010:folio_dup_file_rmap_pte include/linux/rmap.h:544 [inline]
RIP: 0010:copy_present_ptes mm/memory.c:1176 [inline]
RIP: 0010:copy_pte_range mm/memory.c:1304 [inline]
RIP: 0010:copy_pmd_range+0xac8/0x5970 mm/memory.c:1392
Code: e4 18 bf 00 00 00 f4 44 89 e6 e8 a3 21 ad ff 4d 85 f6 0f 85 8b 01 00 00 41 81 fc 00 00 00 f4 0f 84 c3 1a 00 00 e8 48 1d ad ff <48> b8 00 00 00 00 00 fc ff df 48 8b 8c 24 20 01 00 00 80 3c 01 00
RSP: 0018:ffffc900024af300 EFLAGS: 00000293
RAX: ffffffff8218a228 RBX: ffffea0001662018 RCX: ffff88802c245c40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f4000000
RBP: ffffc900024af590 R08: ffffea0001662037 R09: 1ffffd40002cc406
R10: dffffc0000000000 R11: fffff940002cc407 R12: 0000000000000000
R13: 1ffffd40002cc403 R14: 0000000000000000 R15: ffffea0001662000
 copy_pud_range mm/memory.c:1429 [inline]
 copy_p4d_range mm/memory.c:1453 [inline]
 copy_page_range+0xbe8/0x11f0 mm/memory.c:1539
 dup_mmap+0xf40/0x1d90 mm/mmap.c:1840
 dup_mm kernel/fork.c:1534 [inline]
 copy_mm+0x13b/0x4a0 kernel/fork.c:1586
 copy_process+0x1f1c/0x4440 kernel/fork.c:2264
 kernel_clone+0x284/0x8f0 kernel/fork.c:2721
 __do_sys_clone kernel/fork.c:2862 [inline]
 __se_sys_clone kernel/fork.c:2846 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2846
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fecddbc5852
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffcf12a7ac0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffcf12a7ac0 RCX: 00007fecddbc5852
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffcf12a7c4c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555796ab7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000763b5 R15: 00007ffcf12a7ca0
 </TASK>
rcu: rcu_preempt kthread starved for 10485 jiffies! g29949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27968 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6239 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfd4/0x13d0 kernel/smp.c:892
Code: 89 ee 83 e6 01 31 ff e8 da 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 85 03 0c 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 6a 03 0c 00 eb e5 44 89
RSP: 0018:ffffc90004197700 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b873c148 RCX: ffff888030fe8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004197840 R08: ffffffff9030adf7 R09: 1ffffffff20615be
R10: dffffc0000000000 R11: fffffbfff20615bf R12: 1ffff110170c8589
R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2aa878 CR3: 000000000e74a000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 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+0x5f5/0x1160 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:906
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 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
 </TASK>