rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4190/1:b..l (detected by 1, t=10502 jiffies, g=10889, q=100) task:syz-executor state:R running task stack:22000 pid: 4190 ppid: 4182 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90002e3f680 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: d90041a0132e3c00 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980 RBP: ffffc90002e3f7a0 R08: dffffc0000000000 R09: 1ffffffff203a818 R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c31eaa0 R13: 1ffff920005c7edc R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] percpu_ref_get_many include/linux/percpu-refcount.h:202 [inline] percpu_ref_get include/linux/percpu-refcount.h:222 [inline] obj_cgroup_get include/linux/memcontrol.h:805 [inline] memcg_slab_post_alloc_hook mm/slab.h:320 [inline] slab_post_alloc_hook+0x191/0x380 mm/slab.h:526 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 anon_vma_chain_alloc mm/rmap.c:138 [inline] anon_vma_clone+0xbd/0x4f0 mm/rmap.c:284 anon_vma_fork+0x7e/0x500 mm/rmap.c:347 dup_mmap kernel/fork.c:574 [inline] dup_mm kernel/fork.c:1466 [inline] copy_mm+0xa06/0x13f0 kernel/fork.c:1518 copy_process+0x17eb/0x3e20 kernel/fork.c:2290 kernel_clone+0x23f/0x990 kernel/fork.c:2679 __do_sys_clone kernel/fork.c:2796 [inline] __se_sys_clone kernel/fork.c:2780 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fda50145292 RSP: 002b:00007ffc7b195bb0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc7b195bb0 RCX: 00007fda50145292 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc7b195d3c R08: 0000000000000000 R09: 0000000000000001 R10: 0000555572fec7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000001a138 R15: 00007ffc7b195d90 rcu: rcu_preempt kthread starved for 9628 jiffies! g10889 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:28016 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729