On Sat, Jan 26, 2019 at 6:38 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > 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@xxxxxxxxxxxxx> > --- > 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)) Are there other types that should not get mapped? (Or better yet, is there a whitelist of those that are okay to be mapped?) Either way, this sounds good. :) Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -Kees > goto out; > retval = -ENOMEM; > flush_dcache_page(page); > -- > 2.20.1 > -- Kees Cook
