2023-06-06 18:47:10

by Liam R. Howlett

Subject: [PATCH] mm/mprotect: Fix do_mprotect_pkey() limit check

The return of do_mprotect_pkey() can still be incorrectly returned as
success if there is a gap that spans to or beyond the end address passed
in. Update the check to ensure that the end address has indeed been
seen.

Link: https://lore.kernel.org/all/CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@mail.gmail.com/
Fixes: 82f951340f25 ("mm/mprotect: fix do_mprotect_pkey() return on error")
Reported-by: Jeff Xu <[email protected]>
Cc: <[email protected]>
Signed-off-by: Liam R. Howlett <[email protected]>
---
mm/mprotect.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 92d3d3ca390a..c59e7561698c 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -867,7 +867,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
}
tlb_finish_mmu(&tlb);

- if (!error && vma_iter_end(&vmi) < end)
+ if (!error && tmp < end)
error = -ENOMEM;

out:
--
2.39.2

2023-06-06 19:05:14

by Lorenzo Stoakes

Subject: Re: [PATCH] mm/mprotect: Fix do_mprotect_pkey() limit check

On Tue, Jun 06, 2023 at 02:29:12PM -0400, Liam R. Howlett wrote:
> The return of do_mprotect_pkey() can still be incorrectly returned as
> success if there is a gap that spans to or beyond the end address passed
> in. Update the check to ensure that the end address has indeed been
> seen.
>
> Link: https://lore.kernel.org/all/CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@mail.gmail.com/
> Fixes: 82f951340f25 ("mm/mprotect: fix do_mprotect_pkey() return on error")
> Reported-by: Jeff Xu <[email protected]>
> Cc: <[email protected]>
> Signed-off-by: Liam R. Howlett <[email protected]>
> ---
> mm/mprotect.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 92d3d3ca390a..c59e7561698c 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -867,7 +867,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> }
> tlb_finish_mmu(&tlb);
>
> - if (!error && vma_iter_end(&vmi) < end)
> + if (!error && tmp < end)
> error = -ENOMEM;
>
> out:
> --
> 2.39.2
>

As discussed via irc, was able to confirm locally this fixes the reported
issue, so have a quick:-

Reviewed-by: Lorenzo Stoakes <[email protected]>

2023-06-07 07:55:39

by Vlastimil Babka

Subject: Re: [PATCH] mm/mprotect: Fix do_mprotect_pkey() limit check

On 6/6/23 20:29, Liam R. Howlett wrote:
> The return of do_mprotect_pkey() can still be incorrectly returned as
> success if there is a gap that spans to or beyond the end address passed
> in. Update the check to ensure that the end address has indeed been
> seen.
>
> Link: https://lore.kernel.org/all/CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@mail.gmail.com/
> Fixes: 82f951340f25 ("mm/mprotect: fix do_mprotect_pkey() return on error")
> Reported-by: Jeff Xu <[email protected]>
> Cc: <[email protected]>
> Signed-off-by: Liam R. Howlett <[email protected]>

Acked-by: Vlastimil Babka <[email protected]>

> ---
> mm/mprotect.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 92d3d3ca390a..c59e7561698c 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -867,7 +867,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> }
> tlb_finish_mmu(&tlb);
>
> - if (!error && vma_iter_end(&vmi) < end)
> + if (!error && tmp < end)
> error = -ENOMEM;
>
> out:

2023-06-07 07:56:50

by David Hildenbrand

Subject: Re: [PATCH] mm/mprotect: Fix do_mprotect_pkey() limit check

On 06.06.23 20:29, Liam R. Howlett wrote:
> The return of do_mprotect_pkey() can still be incorrectly returned as
> success if there is a gap that spans to or beyond the end address passed
> in. Update the check to ensure that the end address has indeed been
> seen.
>
> Link: https://lore.kernel.org/all/CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@mail.gmail.com/
> Fixes: 82f951340f25 ("mm/mprotect: fix do_mprotect_pkey() return on error")
> Reported-by: Jeff Xu <[email protected]>
> Cc: <[email protected]>
> Signed-off-by: Liam R. Howlett <[email protected]>
> ---
> mm/mprotect.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 92d3d3ca390a..c59e7561698c 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -867,7 +867,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> }
> tlb_finish_mmu(&tlb);
>
> - if (!error && vma_iter_end(&vmi) < end)
> + if (!error && tmp < end)
> error = -ENOMEM;
>
> out:

Acked-by: David Hildenbrand <[email protected]>

--
Cheers,

David / dhildenb