From: Matthew Wilcox <willy@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Rik van Riel <riel@surriel.com>, Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
kernel-hardening@lists.openwall.com,
Kees Cook <keescook@chromium.org>,
Michael Ellerman <mpe@ellerman.id.au>
Subject: [PATCH] mm: Prevent mapping slab pages to userspace
Date: Fri, 25 Jan 2019 09:38:27 -0800 [thread overview]
Message-ID: <20190125173827.2658-1-willy@infradead.org> (raw)
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
next reply other threads:[~2019-01-25 17:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-25 17:38 Matthew Wilcox [this message]
2019-01-25 18:44 ` [PATCH] mm: Prevent mapping slab pages to userspace Kees Cook
2019-01-25 18:44 ` Kees Cook
2019-01-25 19:30 ` Matthew Wilcox
2019-01-28 18:20 ` Andrew Morton
2019-01-28 19:00 ` Kees Cook
2019-01-28 19:00 ` Kees Cook
2019-01-28 20:08 ` Christopher Lameter
2019-01-28 20:08 ` Christopher Lameter
2019-01-31 0:37 ` Michael Ellerman
2019-01-31 0:37 ` Michael Ellerman
2019-01-31 6:03 ` Pekka Enberg
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