rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=da4c/1/0x4000000000000000 softirq=73509/73511 fqs=3 (detected by 0, t=10502 jiffies, g=114897, q=21 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 21401 Comm: syz-executor.5 Not tainted 6.0.0-rc5-syzkaller-00017-gd1221cea11fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1700 [inline] RIP: 0010:__hrtimer_run_queues+0x288/0xe40 kernel/time/hrtimer.c:1749 Code: ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 06 0f 8e f0 0a 00 00 44 0f b6 63 38 31 ff 41 83 e4 01 44 89 e6 e8 d8 e8 0f 00 <45> 84 e4 0f 84 50 08 00 00 e8 4a ec 0f 00 48 8b 54 24 08 48 b8 00 RSP: 0018:ffffc900003f8e40 EFLAGS: 00000046 RAX: 0000000080010001 RBX: ffff888037523b40 RCX: ffffffff816b4bc8 RDX: ffff888034e84200 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880b9b2a640 R14: ffff8880b9b2a540 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 0000000083a08000 CR4: 00000000003526e0 Call Trace: hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x1ef/0x570 kernel/locking/lockdep.c:5634 Code: cf a3 7e 83 f8 01 0f 85 e8 02 00 00 9c 58 f6 c4 02 0f 85 fb 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90003077c98 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200060ef95 RCX: 6b3eed10b5b7c606 RDX: 1ffff110069d098e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff908e1947 R10: fffffbfff211c328 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bf86900 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:280 [inline] rcu_read_lock include/linux/rcupdate.h:706 [inline] percpu_ref_put_many.constprop.0+0x2c/0x1a0 include/linux/percpu-refcount.h:330 percpu_ref_put include/linux/percpu-refcount.h:351 [inline] css_put include/linux/cgroup.h:404 [inline] obj_cgroup_uncharge_pages mm/memcontrol.c:3021 [inline] __memcg_kmem_uncharge_page+0x1d6/0x260 mm/memcontrol.c:3092 memcg_kmem_uncharge_page include/linux/memcontrol.h:1762 [inline] exit_task_stack_account+0xb3/0x110 kernel/fork.c:518 do_exit+0x17cf/0x29b0 kernel/exit.c:837 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb457c89409 Code: Unable to access opcode bytes at RIP 0x7fb457c893df. RSP: 002b:00007ffd7fa7cb08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fb457c89409 RDX: 00007fb457c3c04b RSI: ffffffffffffffb8 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007fb457da0348 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffd7fa7cbf0 rcu: rcu_preempt kthread starved for 10496 jiffies! g114897 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:28352 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1657 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1854 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 18973 Comm: kworker/u4:0 Not tainted 6.0.0-rc5-syzkaller-00017-gd1221cea11fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x46/0x14f lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x206/0x250 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:514 print_other_cpu_stall kernel/rcu/tree_stall.h:619 [inline] check_cpu_stall kernel/rcu/tree_stall.h:762 [inline] rcu_pending kernel/rcu/tree.c:3660 [inline] rcu_sched_clock_irq+0x2404/0x2530 kernel/rcu/tree.c:2342 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:csd_lock_wait kernel/smp.c:414 [inline] RIP: 0010:smp_call_function_many_cond+0x5c8/0x1430 kernel/smp.c:988 Code: 0a 00 85 ed 74 48 48 8b 44 24 08 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 7f b4 0a 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 b5 0b 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc90004927948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9b3f7a0 RCX: 0000000000000000 RDX: ffff8880211ca200 RSI: ffffffff817083a1 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1017367ef5 R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1154 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1302 [inline] text_poke_bp_batch+0x233/0x6c0 arch/x86/kernel/alternative.c:1490 text_poke_flush arch/x86/kernel/alternative.c:1660 [inline] text_poke_flush arch/x86/kernel/alternative.c:1657 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1667 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:801 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:811 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:803 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306