rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=ca3c/1/0x4000000000000000 softirq=52259/52259 fqs=5 rcu: (detected by 0, t=10502 jiffies, g=47141, q=323 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11856 Comm: syz.7.1879 Not tainted 6.12.0-rc6-syzkaller-00005-g557329bcecc2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:65 Code: d1 fc ff e8 02 7d ff ff eb a8 e8 4b e0 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 60 08 61 8c e9 bd fe ff ff 66 2e 0f RSP: 0018:ffffc90000a189f8 EFLAGS: 00000096 RAX: 0000000000000001 RBX: ffffc90000a18a60 RCX: 0199023abde9f400 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8c0adc40 RBP: ffffc90000a18b48 R08: ffffffff942cd807 R09: 1ffffffff2859b00 R10: dffffc0000000000 R11: fffffbfff2859b01 R12: 1ffff92000143148 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000046 FS: 00007f328e4516c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555594ee6808 CR3: 000000006b866000 CR4: 0000000000350ef0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_acquire+0x1fd/0x550 kernel/locking/lockdep.c:5827 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_activate+0x16d/0x510 lib/debugobjects.c:708 debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline] debug_activate kernel/time/hrtimer.c:478 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1708 [inline] __hrtimer_run_queues+0x6cb/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_check_range+0xb/0x290 mm/kasan/generic.c:188 Code: 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 41 57 41 56 41 54 <53> b0 01 48 85 f6 0f 84 a0 01 00 00 4c 8d 04 37 49 39 f8 0f 82 56 RSP: 0018:ffffc90003b4f1c8 EFLAGS: 00000246 RAX: 1ffff11003d83831 RBX: ffff8880311f44b8 RCX: ffffffff8bc011de RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880311f44b8 RBP: 0000000000000008 R08: ffff8880311f44b0 R09: 1ffff1100623e896 R10: dffffc0000000000 R11: ffffed100623e897 R12: ffff88801ec1c188 R13: ffff8880311f44b0 R14: 0000000000000008 R15: 0000000000000000 read_word_at_a_time+0xe/0x20 include/asm-generic/rwonce.h:85 sized_strscpy+0x8d/0x220 lib/string.c:143 __update_page_owner_handle mm/page_owner.c:251 [inline] __set_page_owner+0x285/0x800 mm/page_owner.c:325 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x303f/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2283 shmem_alloc_folio mm/shmem.c:1771 [inline] shmem_alloc_and_add_folio+0x49b/0x13d0 mm/shmem.c:1810 shmem_get_folio_gfp+0x5a9/0x20a0 mm/shmem.c:2332 shmem_get_folio mm/shmem.c:2438 [inline] shmem_write_begin+0x17e/0x460 mm/shmem.c:3043 generic_perform_write+0x346/0x6d0 mm/filemap.c:4054 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3218 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xaed/0xd30 fs/read_write.c:683 ksys_write+0x183/0x2b0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f328d57d1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48 RSP: 002b:00007f328e450df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f328d57d1ff RDX: 0000000001000000 RSI: 00007f3283400000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000004425 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f328e450ef0 R14: 00007f328e450eb0 R15: 00007f3283400000 rcu: rcu_preempt kthread starved for 10492 jiffies! g47141 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:25824 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 61 Comm: kworker/u8:4 Not tainted 6.12.0-rc6-syzkaller-00005-g557329bcecc2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2ca0 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 86 f3 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 31 ef 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 15 ef RSP: 0018:ffffc900015c76e0 EFLAGS: 00000293 RAX: ffffffff8188eb4b RBX: 1ffff110170e8919 RCX: ffff88801bf9da00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900015c78e0 R08: ffffffff8188eb1a R09: 1ffffffff2859b00 R10: dffffc0000000000 R11: fffffbfff2859b01 R12: dffffc0000000000 R13: ffff8880b87448c8 R14: ffff8880b863fc80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff8236656c0 CR3: 000000000e734000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244