rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8941/3:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=40401, q=183 ncpus=2)
task:syz.4.756       state:R  running task     stack:27320 pid:8941  tgid:8941  ppid:6031   task_flags:0x400040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0x1939/0x1fa0 mm/filemap.c:3931
 do_fault_around mm/memory.c:5713 [inline]
 do_read_fault mm/memory.c:5746 [inline]
 do_fault mm/memory.c:5889 [inline]
 do_pte_missing+0x20b2/0x3330 mm/memory.c:4401
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580
 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f7a2886f2ed
RSP: 002b:00007ffd439dad40 EFLAGS: 00010202
RAX: 000000110c38c000 RBX: 00007f7a29715720 RCX: 0000000000000005
RDX: 0000000000001feb RSI: 00000000000018ff RDI: 0000000000000020
RBP: ffffffff81763feb R08: 00007f7a28be6038 R09: 00007f7a28bd2000
R10: 00007f7a283ff008 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff81763feb R15: 000000000000002d
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g40401 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:27168 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 __schedule_loop kernel/sched/core.c:6948 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6963
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 150 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90000a08da0 EFLAGS: 00000206
RAX: 8061b99abf74f800 RBX: 0000000000000a06 RCX: 8061b99abf74f800
RDX: 0000000000000002 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc90000a08e30 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000009 R14: ffff8880b8728240 R15: 1ffff920001411b4
FS:  0000000000000000(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51e24a0d58 CR3: 000000000e138000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 handle_softirqs+0x27d/0x850 kernel/softirq.c:626
 __do_softirq kernel/softirq.c:660 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 aa a6 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 55 a2 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 39 a2
RSP: 0018:ffffc90002e67660 EFLAGS: 00000293
RAX: ffffffff81b65627 RBX: 1ffff110170c85d1 RCX: ffff88801e328000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002e677e0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: ffff8880b8642e88
R13: dffffc0000000000 R14: ffff8880b873bd40 R15: 0000000000000000
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
 smp_text_poke_batch_finish+0xb44/0x1130 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+0xad/0x240 mm/kfence/core.c:874
 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
 process_scheduled_works kernel/workqueue.c:3362 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>