2022-07-09 09:45:55

by Miaohe Lin

Subject: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte

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 <[email protected]>
---
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;
--
2.23.0

2022-07-11 11:13:40

by Muchun Song

Subject: Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte

On Sat, Jul 09, 2022 at 05:26:29PM +0800, 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 <[email protected]>

Acked-by: Muchun Song <[email protected]>

Thanks.

2022-07-11 21:13:16

by Mike Kravetz

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 <[email protected]>
> ---
> mm/hugetlb.c | 1 +
> 1 file changed, 1 insertion(+)

Thanks for finding and fixing!

Reviewed-by: Mike Kravetz <[email protected]>
--
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
>

2022-07-12 03:29:38

by Baolin Wang

Subject: Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte

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 <[email protected]>

Reviewed-by: Baolin Wang <[email protected]>

> ---
> 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;

2022-07-12 08:21:34

by Anshuman Khandual

Subject: Re: [PATCH] hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte

On 7/9/22 14:56, 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 <[email protected]>

Reviewed-by: Anshuman Khandual <[email protected]>

> ---
> 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;