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From: Christopher Lameter <cl@linux.com>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Matthew Wilcox <willy@infradead.org>,
	Linux-MM <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Rik van Riel <riel@surriel.com>,
	Pekka Enberg <penberg@kernel.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH] mm: Prevent mapping slab pages to userspace
Date: Mon, 28 Jan 2019 20:08:23 +0000	[thread overview]
Message-ID: <010001689613c1b5-6539225d-b74e-4248-8d8f-5b801c1a333b-000000@email.amazonses.com> (raw)
In-Reply-To: <CAGXu5jJkf4pKr0WVUcFitZnnUbq3annautZxzYPC0TQaB5HaGA@mail.gmail.com>

On Tue, 29 Jan 2019, Kees Cook wrote:

> It seems like a fatal condition to me? There's nothing to check that
> such a page wouldn't get freed by the slab while still mapped to
> userspace, right?

Lets just fail the code.  Currently this may work with SLUB. But SLAB and
SLOB overlay fields with mapcount. So you would have a corrupted page
struct if you mapped a slab page to user space.

  reply	other threads:[~2019-01-28 20:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-25 17:38 [PATCH] mm: Prevent mapping slab pages to userspace Matthew Wilcox
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 20:08     ` Christopher Lameter [this message]
2019-01-31  0:37 ` Michael Ellerman
2019-01-31  6:03 ` Pekka Enberg

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