Re: [PATCH 5/6] mm/hugetlb: fix sysfs group leak in hugetlb_unregister_node()

["Yin, Fengwei" <fengwei.yin@xxxxxxxxx>]

Hi Miaohe,

On 8/16/2022 9:05 PM, Miaohe Lin wrote:
> }
>  
>  	if (h->demote_order) {
> -		if (sysfs_create_group(hstate_kobjs[hi],
> -					&hstate_demote_attr_group))
> +		retval = sysfs_create_group(hstate_kobjs[hi],
> +					    &hstate_demote_attr_group);
What about add one more:
   just return if hstate_attr_group creating failed:

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0aee2f3ae15c..a67ef4b4eb3f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3845,6 +3845,7 @@ static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
        if (retval) {
                kobject_put(hstate_kobjs[hi]);
                hstate_kobjs[hi] = NULL;
+               return retval;
        }

Once hstate_kobjs[hi] is set to NULL, hstate_demote_attr_group creating will
fail as well. Thanks.


Regards
Yin, Fengwei

> +		if (retval) {
>  			pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name);
> +			sysfs_remove_group(hstate_kobjs[hi], hstate_attr_group);
> +			kobject_put(hstate_kobjs[hi]);
> +			hstate_kobjs[hi] = NULL;
> +			return retval;
> +		}
>  	}