Date: Tue, 18 Apr 2017 08:37:13 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
To: Michal Hocko <mhocko@kernel.org>
cc: Kees Cook <keescook@chromium.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: Add additional consistency check
In-Reply-To: <20170418064124.GA22360@dhcp22.suse.cz>
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On Tue, 18 Apr 2017, Michal Hocko wrote:

> Are you even reading those emails? First of all we are talking about
> slab here. Secondly I've already pointed out that the BUG_ON(!PageSlab)
> in kmem_freepages is already too late because we do operate on a
> potential garbage from invalid page...

Before I forget:

1. The patch affects both slab and slub since it patches mm/slab.h and is
called by both allocators.

2. The check in the patch we are discussing here when calling
kmem_cache_free() will be executing before kmem_freepages() is called
in slab.