From: Qian Cai <cai@lca.pw>
To: Alexander Potapenko <glider@google.com>, akpm@linux-foundation.org
Cc: linux-security-module@vger.kernel.org, linux-mm@kvack.org,
ndesaulniers@google.com, kcc@google.com, dvyukov@google.com,
keescook@chromium.org, sspatil@android.com, labbott@redhat.com,
kernel-hardening@lists.openwall.com
Subject: Re: [PATCH] mm: security: introduce CONFIG_INIT_HEAP_ALL
Date: Fri, 12 Apr 2019 10:16:24 -0400 [thread overview]
Message-ID: <1555078584.26196.50.camel@lca.pw> (raw)
In-Reply-To: <20190412124501.132678-1-glider@google.com>
On Fri, 2019-04-12 at 14:45 +0200, Alexander Potapenko wrote:
> This config option adds the possibility to initialize newly allocated
> pages and heap objects with zeroes. This is needed to prevent possible
> information leaks and make the control-flow bugs that depend on
> uninitialized values more deterministic.
>
> Initialization is done at allocation time at the places where checks for
> __GFP_ZERO are performed. We don't initialize slab caches with
> constructors or SLAB_TYPESAFE_BY_RCU to preserve their semantics.
>
> For kernel testing purposes filling allocations with a nonzero pattern
> would be more suitable, but may require platform-specific code. To have
> a simple baseline we've decided to start with zero-initialization.
>
> No performance optimizations are done at the moment to reduce double
> initialization of memory regions.
Sounds like this has already existed in some degree, i.e.,
CONFIG_PAGE_POISONING_ZERO
next prev parent reply other threads:[~2019-04-12 14:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-12 12:45 Alexander Potapenko
2019-04-12 14:16 ` Qian Cai [this message]
2019-04-12 15:23 ` Alexander Potapenko
2019-04-16 2:02 ` Andrew Morton
2019-04-16 8:33 ` Vlastimil Babka
2019-04-16 12:21 ` Alexander Potapenko
2019-04-16 8:30 ` Vlastimil Babka
2019-04-16 12:04 ` Alexander Potapenko
2019-04-16 15:32 ` Christopher Lameter
2019-04-16 16:01 ` Alexander Potapenko
2019-04-16 16:30 ` Christopher Lameter
2019-04-17 11:03 ` Alexander Potapenko
2019-04-17 17:04 ` Alexander Potapenko
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