syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11674/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=54821, q=393 ncpus=2)
task:kvm-nx-lpage-re state:R  running task     stack:26488 pid:11674 tgid:11674 ppid:2      flags:0x00024000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 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:unwind_get_return_address+0x83/0xc0 arch/x86/kernel/unwind_orc.c:369
Code: d3 71 1e 00 89 c5 31 ff 89 c6 e8 c8 6b 52 00 85 ed 74 20 e8 7f 67 52 00 43 80 3c 37 00 74 08 48 89 df e8 50 83 b6 00 48 8b 03 <eb> 0e e8 66 67 52 00 eb 05 e8 5f 67 52 00 31 c0 5b 41 5e 41 5f 5d
RSP: 0018:ffffc90002f77478 EFLAGS: 00000246
RAX: ffffffff8189f487 RBX: ffffc90002f774e8 RCX: ffff88807b853c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff814125f8 R09: ffffffff814140bf
R10: 0000000000000003 R11: ffff88807b853c00 R12: ffff88807b853c00
R13: ffffffff817f3070 R14: dffffc0000000000 R15: 1ffff920005eee9d
 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+0x76/0x430 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd19/0xea0 mm/page_alloc.c:2612
 discard_slab mm/slub.c:2583 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3051
 put_cpu_partial+0x17c/0x250 mm/slub.c:3126
 __slab_free+0x2ea/0x3d0 mm/slub.c:4343
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 __kmalloc_cache_noprof+0x132/0x2c0 mm/slub.c:4184
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 find_css_set+0xb07/0x1720 kernel/cgroup/cgroup.c:1194
 cgroup_migrate_prepare_dst+0x124/0x690 kernel/cgroup/cgroup.c:2797
 cgroup_attach_task+0x697/0xaf0 kernel/cgroup/cgroup.c:2901
 cgroup_attach_task_all+0x9e/0xe0 kernel/cgroup/cgroup-v1.c:70
 kvm_vm_worker_thread+0x39b/0x580 virt/kvm/kvm_main.c:6643
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: rcu_preempt kthread starved for 2138 jiffies! g54821 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:25816 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
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:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111