From: Matthew Wilcox <willy@infradead.org>
To: Ilya Smith <blackzert@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Michal Hocko <mhocko@suse.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Jan Kara <jack@suse.cz>, Jerome Glisse <jglisse@redhat.com>,
Hugh Dickins <hughd@google.com>, Helge Deller <deller@gmx.de>,
Andrea Arcangeli <aarcange@redhat.com>,
Oleg Nesterov <oleg@redhat.com>, Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>
Subject: Re: [RFC PATCH] Randomization of address chosen by mmap.
Date: Fri, 2 Mar 2018 12:48:08 -0800 [thread overview]
Message-ID: <20180302204808.GA671@bombadil.infradead.org> (raw)
In-Reply-To: <C9D0E3BA-3AB9-4F0E-BDA5-32378E440986@gmail.com>
On Fri, Mar 02, 2018 at 11:30:28PM +0300, Ilya Smith wrote:
> This is a really good question. Lets think we choose address with random-length
> guard hole. This length is limited by some configuration as you described. For
> instance let it be 1MB. Now according to current implementation, we still may
> fill this gap with small allocations with size less than 1MB. Attacker will
> going to build attack base on this predictable behaviour - he jus need to spray
> with 1 MB chunks (or less, with some expectation). This attack harder but not
> impossible.
Ah, I didn't mean that. I was thinking that we can change the
implementation to reserve 1-N pages after the end of the mapping.
So you can't map anything else in there, and any load/store into that
region will segfault.
next prev parent reply other threads:[~2018-03-02 20:48 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-27 13:13 [RFC PATCH] Randomization of address chosen by mmap Ilya Smith
2018-02-27 20:52 ` Kees Cook
2018-02-27 21:31 ` lazytyped
2018-02-28 17:13 ` Ilya Smith
2018-02-28 18:33 ` Matthew Wilcox
2018-02-28 21:02 ` Daniel Micay
2018-03-03 13:58 ` Ilya Smith
2018-03-03 21:00 ` Daniel Micay
2018-03-04 3:47 ` Matthew Wilcox
2018-03-04 20:56 ` Matthew Wilcox
2018-03-05 13:09 ` Ilya Smith
2018-03-05 14:23 ` Daniel Micay
2018-03-05 16:05 ` Ilya Smith
2018-03-05 16:23 ` Matthew Wilcox
2018-03-05 19:27 ` Ilya Smith
2018-03-05 19:47 ` Matthew Wilcox
2018-03-05 20:20 ` Ilya Smith
2018-03-02 20:30 ` Ilya Smith
2018-03-02 20:48 ` Matthew Wilcox [this message]
2018-03-03 15:13 ` Ilya Smith
2018-02-28 19:54 ` Kees Cook
2018-03-01 13:52 ` Ilya Smith
2018-03-02 7:17 ` 097eb0af45: kernel_BUG_at_mm/hugetlb.c kernel test robot
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