rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (3 ticks this GP) idle=e05c/1/0x4000000000000000 softirq=8135/8151 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=9245, q=310 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5236 Comm: udevd Not tainted 6.9.0-syzkaller-12398-gc13320499ba0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:__lock_acquire+0xe4d/0x1fd0 Code: da 48 8b 3c 24 e8 53 6d 89 00 eb cf 49 89 fd 48 c7 c7 20 0f 20 8e 48 89 ee e8 6f 9f 76 03 4c 89 ef eb 8a 89 d8 25 ff 1f 00 00 eb 03 81 e3 00 60 00 00 09 c3 4c 89 e0 48 c1 e8 20 29 c3 89 c1 RSP: 0018:ffffc90000a18950 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 00000000000c4001 RCX: ffff88801570a8e0 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff88801570a980 R08: ffffffff92fa8587 R09: 1ffffffff25f50b0 R10: dffffc0000000000 R11: fffffbfff25f50b1 R12: 3be9ba32c8301548 R13: ffff888015709e00 R14: 0000000000000000 R15: ffff888015709e00 FS: 00007f0e31db1c80(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e31566731 CR3: 000000006a950000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __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_deactivate+0x158/0x390 lib/debugobjects.c:763 debug_hrtimer_deactivate kernel/time/hrtimer.c:428 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:484 __run_hrtimer kernel/time/hrtimer.c:1655 [inline] __hrtimer_run_queues+0x305/0xd50 kernel/time/hrtimer.c:1751 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1813 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 1a 80 89 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000362f9e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920006c5f48 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcacc00 RDI: ffffffff8c1ff140 RBP: ffffc9000362fb40 R08: ffffffff92fa8597 R09: 1ffffffff25f50b2 R10: dffffc0000000000 R11: fffffbfff25f50b3 R12: 1ffff920006c5f44 R13: dffffc0000000000 R14: ffffc9000362fa40 R15: 0000000000000246 fs_reclaim_acquire+0xaf/0x140 mm/page_alloc.c:3800 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3890 [inline] slab_alloc_node mm/slub.c:3980 [inline] kmalloc_trace_noprof+0x3d/0x2c0 mm/slub.c:4147 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] task_numa_work+0x854/0x13f0 kernel/sched/fair.c:3313 task_work_run+0x251/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0e3189a93b Code: 48 8b 15 f0 64 15 00 83 c8 ff 64 83 3a 15 75 0e 48 8b 7c 24 08 e8 d5 d4 07 00 f7 d8 19 c0 48 83 c4 18 c3 b8 52 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 be 64 15 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffea44c4de8 EFLAGS: 00000206 ORIG_RAX: 0000000000000052 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00007f0e3189a93b RDX: 000055b3d1c58e64 RSI: 00007ffea44c4e08 RDI: 00007ffea44c5208 RBP: 000055b68aac22a0 R08: 0000000000000006 R09: 85b69ed5ca3d5ffa R10: 000000000000010f R11: 0000000000000206 R12: 000055b68aad4e30 R13: 00007ffea44c4e08 R14: 00007ffea44c5208 R15: 000055b680581ec8 rcu: rcu_preempt kthread starved for 10497 jiffies! g9245 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:25584 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 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 PID: 11 Comm: kworker/u8:0 Not tainted 6.9.0-syzkaller-12398-gc13320499ba0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1865/0x29d0 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 99 09 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 44 05 0c 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 28 05 0c 00 eb e4 44 RSP: 0018:ffffc90000107700 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110172a88a9 RCX: ffff888016ebbc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001078e0 R08: ffffffff818a1127 R09: 1ffffffff25f50b0 R10: dffffc0000000000 R11: fffffbfff25f50b1 R12: dffffc0000000000 R13: ffff8880b9544548 R14: ffff8880b943f900 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff29b40e98 CR3: 000000000e132000 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:2069 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2279 text_poke_flush arch/x86/kernel/alternative.c:2470 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2477 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:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 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