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    Subject[PATCH] mm: Prevent mapping slab pages to userspace
    Date
    It's never appropriate to map a page allocated by SLAB into userspace.
    A buggy device driver might try this, or an attacker might be able to
    find a way to make it happen.

    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 e11ca9dd823f..ce8c90b752be 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))
    + if (PageAnon(page) || PageSlab(page))
    goto out;
    retval = -ENOMEM;
    flush_dcache_page(page);
    --
    2.20.1
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