Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH] mm: Prevent mapping slab pages to userspace | Date | Thu, 31 Jan 2019 11:37:10 +1100 |
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Matthew Wilcox <willy@infradead.org> writes:
> 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);
Thanks for turning this into an actual patch.
cheers
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