rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4724/1:b..l (detected by 0, t=10502 jiffies, g=9773, q=108) task:syz.3.120 state:R running task stack:26424 pid: 4724 ppid: 4176 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline] RIP: 0010:lock_release+0x156/0x9a0 kernel/locking/lockdep.c:5639 Code: 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 ec 79 67 00 4c 89 6c 24 50 48 c7 84 24 b0 00 00 00 00 00 00 00 9c <8f> 84 24 b0 00 00 00 42 80 3c 3b 00 74 08 4c 89 f7 e8 44 79 67 00 RSP: 0018:ffffc900032ef7f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff9200065df16 RCX: ffffffff8162f3e8 RDX: 0000000000000000 RSI: ffffffff8af9f2a0 RDI: ffffffff8af9f260 RBP: ffffc900032ef930 R08: dffffc0000000000 R09: fffffbfff1c150ee R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200065df0c R13: ffffffff81cfdad0 R14: ffffc900032ef8b0 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:772 [inline] percpu_ref_tryget_many include/linux/percpu-refcount.h:250 [inline] percpu_ref_tryget+0xcd/0x140 include/linux/percpu-refcount.h:266 obj_cgroup_tryget include/linux/memcontrol.h:800 [inline] get_obj_cgroup_from_current mm/memcontrol.c:2927 [inline] __memcg_kmem_charge_page+0x256/0x3a0 mm/memcontrol.c:3053 memcg_kmem_charge_page include/linux/memcontrol.h:1696 [inline] memcg_charge_kernel_stack kernel/fork.c:417 [inline] dup_task_struct+0x249/0xb60 kernel/fork.c:903 copy_process+0x5eb/0x3ef0 kernel/fork.c:2036 kernel_clone+0x210/0x960 kernel/fork.c:2603 __do_sys_clone3 kernel/fork.c:2878 [inline] __se_sys_clone3+0x3e1/0x430 kernel/fork.c:2862 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3a28f2c649 RSP: 002b:00007ffeeb40b678 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007f3a28eaea30 RCX: 00007f3a28f2c649 RDX: 00007f3a28eaea30 RSI: 0000000000000058 RDI: 00007ffeeb40b6c0 RBP: 00007f3a26d406c0 R08: 00007f3a26d406c0 R09: 00007ffeeb40b7a7 R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8 R13: 000000000000006e R14: 00007ffeeb40b6c0 R15: 00007ffeeb40b7a8 rcu: rcu_preempt kthread starved for 10530 jiffies! g9773 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:27256 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562