Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte

[Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>]

On 7/9/2022 5:26 PM, Miaohe Lin wrote:
> When alloc_huge_page fails, *pagep is set to NULL without put_page first.
> So the hugepage indicated by *pagep is leaked.
>
> Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY")
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>

Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>

> ---
>   mm/hugetlb.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 06c2d86b1ba3..598c37279fee 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -5962,6 +5962,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
>   
>   		page = alloc_huge_page(dst_vma, dst_addr, 0);
>   		if (IS_ERR(page)) {
> +			put_page(*pagep);
>   			ret = -ENOMEM;
>   			*pagep = NULL;
>   			goto out;