Date: Tue, 4 Apr 2017 14:58:06 -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@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: Add additional consistency check
In-Reply-To: <20170404194220.GT15132@dhcp22.suse.cz>
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References: <20170331164028.GA118828@beast> <20170404113022.GC15490@dhcp22.suse.cz> <alpine.DEB.2.20.1704041005570.23420@east.gentwo.org> <20170404151600.GN15132@dhcp22.suse.cz> <alpine.DEB.2.20.1704041412050.27424@east.gentwo.org>
 <20170404194220.GT15132@dhcp22.suse.cz>
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On Tue, 4 Apr 2017, Michal Hocko wrote:

> On Tue 04-04-17 14:13:06, Cristopher Lameter wrote:
> > On Tue, 4 Apr 2017, Michal Hocko wrote:
> >
> > > Yes, but we do not have to blow the kernel, right? Why cannot we simply
> > > leak that memory?
> >
> > Because it is a serious bug to attempt to free a non slab object using
> > slab operations. This is often the result of memory corruption, coding
> > errs etc. The system needs to stop right there.
>
> Why when an alternative is a memory leak?

Because the slab allocators fail also in case you free an object multiple
times etc etc. Continuation is supported by enabling a special resiliency
feature via the kernel command line. The alternative is selectable but not
the default.