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: Wed, 28 Feb 2018 10:33:49 -0800 [thread overview]
Message-ID: <20180228183349.GA16336@bombadil.infradead.org> (raw)
In-Reply-To: <55C92196-5398-4C19-B7A7-6C122CD78F32@gmail.com>
On Wed, Feb 28, 2018 at 08:13:00PM +0300, Ilya Smith wrote:
> > It would be worth spelling out the "not recommended" bit some more
> > too: this fragments the mmap space, which has some serious issues on
> > smaller address spaces if you get into a situation where you cannot
> > allocate a hole large enough between the other allocations.
> >
>
> Ia??m agree, that's the point.
Would it be worth randomising the address returned just ever so slightly?
ie instead of allocating exactly the next address, put in a guard hole
of (configurable, by default maybe) 1-15 pages? Is that enough extra
entropy to foil an interesting number of attacks, or do we need the full
randomise-the-address-space approach in order to be useful?
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next prev parent reply other threads:[~2018-02-28 18:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-27 13:13 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 [this message]
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
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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