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authorMatthew Wilcox <willy@infradead.org>2019-03-06 00:46:06 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-06 06:07:17 +0100
commit0ee930e6cafa048c1925893d0ca89918b2814f2c (patch)
tree583057c2957c316cbb52378c8758c408b676d216 /mm
parentmm: prevent mapping slab pages to userspace (diff)
downloadlinux-0ee930e6cafa048c1925893d0ca89918b2814f2c.tar.xz
linux-0ee930e6cafa048c1925893d0ca89918b2814f2c.zip
mm/memory.c: prevent mapping typed pages to userspace
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. Link: http://lkml.kernel.org/r/20190129053830.3749-1-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index a9897dcd530f..79e0173a7d70 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1452,7 +1452,7 @@ 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);