linux-kernel - Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic

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Message-ID: <YsyP2h/zIwJhp33s@monkey>
Date:   Mon, 11 Jul 2022 14:02:18 -0700
From:   Mike Kravetz <mike.kravetz@...cle.com>
To:     Miaohe Lin <linmiaohe@...wei.com>
Cc:     akpm@...ux-foundation.org, songmuchun@...edance.com,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte

On 07/09/22 17:26, 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@...wei.com>
> ---
>  mm/hugetlb.c | 1 +
>  1 file changed, 1 insertion(+)

Thanks for finding and fixing!

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


> 
> 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;
> -- 
> 2.23.0
>