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SubjectRe: [PATCH] mm: Prevent mapping typed pages to userspace
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On 29.01.19 06:38, Matthew Wilcox wrote:
> Pages which use page_type must never be mapped to userspace as it would
> destroy their page type. Add an explicit check for this instead of
> assuming that kernel drivers always get this right.
>
> Signed-off-by: Matthew Wilcox <willy@infradead.org>
> ---
> mm/memory.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index ce8c90b752be..db3534bbd652 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1451,7 +1451,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
> spinlock_t *ptl;
>
> retval = -EINVAL;
> - if (PageAnon(page) || PageSlab(page))
> + if (PageAnon(page) || PageSlab(page) || page_has_type(page))
> goto out;
> retval = -ENOMEM;
> flush_dcache_page(page);
>

Reviewed-by: David Hildenbrand <david@redhat.com>

--

Thanks,

David / dhildenb

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