rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=0bf4/1/0x4000000000000000 softirq=9469/9470 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5623/1:b..l rcu: (detected by 1, t=10506 jiffies, g=11177, q=295 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4533 Comm: udevd Not tainted 6.9.0-rc5-syzkaller-00042-ge88c4cfcb7b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:lock_acquire+0x6d/0x550 kernel/locking/lockdep.c:5722 Code: 24 00 01 00 00 49 bd 00 00 00 00 00 fc ff df 48 c7 44 24 40 b3 8a b5 41 48 c7 44 24 48 81 6e b0 8d 48 c7 44 24 50 d0 7a 72 81 <4c> 8d 64 24 40 49 c1 ec 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4b 89 04 RSP: 0018:ffffc900000078e0 EFLAGS: 00000082 RAX: 78d6b0dcf258d200 RBX: ffffffff84b6ddd0 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff8ea354c0 RBP: ffffc90000007a28 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52000000f8e R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88801be8a340 FS: 00007fa79b36bc80(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8ada4a4440 CR3: 000000002dfd4000 CR4: 0000000000350ef0 Call Trace: debug_objects_fill_pool+0x9f/0x9b0 lib/debugobjects.c:614 debug_object_activate+0x135/0x510 lib/debugobjects.c:704 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:1090 __run_hrtimer kernel/time/hrtimer.c:1709 [inline] __hrtimer_run_queues+0x6d5/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:207 Code: c0 d3 03 00 65 8b 15 50 d2 6d 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 14 16 00 00 00 74 2c 8b 91 f0 15 00 00 <83> fa 02 75 21 48 8b 91 f8 15 00 00 48 8b 32 48 8d 7e 01 8b 89 f4 RSP: 0018:ffffc900098d73b0 EFLAGS: 00000246 RAX: ffffffff81417709 RBX: ffffc900098d7918 RCX: ffff88807e2bbc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffc900098d7918 RBP: 1ffff9200131ae96 R08: ffffffff8141500d R09: ffffffff81414f66 R10: 0000000000000003 R11: ffff88807e2bbc00 R12: ffffc900098d7918 R13: dffffc0000000000 R14: 1ffff9200131ae95 R15: 1ffff9200131ae94 __read_once_word_nocheck+0x9/0x20 include/asm-generic/rwonce.h:66 deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0x1356/0x2a00 arch/x86/kernel/unwind_orc.c:585 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc+0x174/0x340 mm/slub.c:3852 kmem_cache_zalloc include/linux/slab.h:739 [inline] alloc_empty_file+0x9e/0x1d0 fs/file_table.c:202 path_openat+0xfb/0x3240 fs/namei.c:3785 do_filp_open+0x235/0x490 fs/namei.c:3826 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa79af169a4 Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffff4ad1480 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fa79af169a4 RDX: 0000000000080000 RSI: 00007ffff4ad15b8 RDI: 00000000ffffff9c RBP: 00007ffff4ad15b8 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 0000557de1242b42 R14: 0000000000000001 R15: 0000000000000000 task:rm state:R running task stack:23800 pid:5623 tgid:5623 ppid:5593 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:206 Code: 8b 3d 6c 10 3f 0c 48 89 de 5b e9 c3 f1 58 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 c0 d3 03 00 65 8b 15 50 d2 6d 7e f7 c2 00 01 ff 00 RSP: 0018:ffffc9000415f1b0 EFLAGS: 00000202 RAX: ffffffff81413e21 RBX: ffffc9000415f228 RCX: ffffffff90fd8000 RDX: ffff88806bc4da00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff81413e18 R09: ffffffff814158df R10: 0000000000000003 R11: ffff88806bc4da00 R12: ffff88806bc4da00 R13: ffffffff8181e0a0 R14: dffffc0000000000 R15: 1ffff9200082be45 unwind_get_return_address+0x71/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:302 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347 free_unref_folios+0x185/0xb30 mm/page_alloc.c:2536 folios_put_refs+0x8eb/0xa10 mm/swap.c:1034 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:329 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x4bb/0xd60 mm/mmap.c:3280 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:569 do_exit+0x99e/0x27e0 kernel/exit.c:865 do_group_exit+0x207/0x2c0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ada562a90 RSP: 002b:00007ffffc350a18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f8ada653860 RCX: 00007f8ada562a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00007f8ada653860 R08: 00007ffffc350890 R09: 00007ffffc350970 R10: 00007ffffc3508d0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8ada657658 R15: 0000000000000001 rcu: rcu_preempt kthread starved for 10495 jiffies! g11177 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:26256 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f2/0x390 kernel/kthread.c:388 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: 1 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00042-ge88c4cfcb7b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 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 a4 d6 0b 00 eb e4 44 RSP: 0018:ffffc900001076e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017288c6d RCX: ffff888016eebc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001078e0 R08: ffffffff818a2a8b R09: 1ffffffff25e68a0 R10: dffffc0000000000 R11: fffffbfff25e68a1 R12: dffffc0000000000 R13: ffff8880b9446368 R14: ffff8880b953f7c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000600 CR3: 000000000e134000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2086 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244