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Message-ID: <801e4f05-6097-4537-9715-2e00a3990f7d@linux.alibaba.com>
Date:   Tue, 12 Jul 2022 11:00:55 +0800
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Subject: Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte
To:     Miaohe Lin <linmiaohe@huawei.com>, akpm@linux-foundation.org,
        mike.kravetz@oracle.com, songmuchun@bytedance.com
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20220709092629.54291-1-linmiaohe@huawei.com>
From:   Baolin Wang <baolin.wang@linux.alibaba.com>
In-Reply-To: <20220709092629.54291-1-linmiaohe@huawei.com>
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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@huawei.com>

Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

> ---
>   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;