Re: [PATCH 2/6] mm/hugetlb: fix WARN_ON(!kobj) in sysfs_create_group()

From: Mike Kravetz
Date: Tue Aug 16 2022 - 18:56:13 EST


On 08/16/22 21:05, Miaohe Lin wrote:
> If sysfs_create_group() fails with hstate_attr_group, hstate_kobjs[hi]
> will be set to NULL. Then it will be passed to sysfs_create_group() if
> h->demote_order != 0 thus triggering WARN_ON(!kobj) check. Fix this by
> making sure hstate_kobjs[hi] != NULL when calling sysfs_create_group.
>
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> ---
> mm/hugetlb.c | 1 +
> 1 file changed, 1 insertion(+)

Thanks!

Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
--
Mike Kravetz

>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index e72052964fb5..ff991e5bdf1f 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3846,6 +3846,7 @@ 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;
> }
>
> if (h->demote_order) {
> --
> 2.23.0
>