Re: [PATCH 1/1] mm/slub.c: add a naive detection of double free or corruption

From	Christopher Lameter <cl@linux.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/1] mm/slub.c: add a naive detection of double free or corruption
Date	2017-07-19 16:10 +0200
Message-ID	<u4XPQ-1bD-29@gated-at.bofh.it> (permalink)
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On Tue, 18 Jul 2017, Kees Cook wrote:

> I think there are two issues: first, this should likely be under
> CONFIG_FREELIST_HARDENED since Christoph hasn't wanted to make these
> changes enabled by default (if I'm understanding his earlier review
> comments to me). The second issue is what to DO when a double-free is
> discovered. Is there any way to make it safe/survivable? If not, I

The simple thing is to not free the object when you discover this. That is
what the existing debugging code does. But you do not have an easy way to
fail at the point in the code that is patched here.

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Re: [PATCH 1/1] mm/slub.c: add a naive detection of double free or  corruption Alexander Popov <alex.popov@linux.com> - 2017-07-18 22:00 +0200
  Re: [PATCH 1/1] mm/slub.c: add a naive detection of double free or corruption Kees Cook <keescook@chromium.org> - 2017-07-18 22:10 +0200
    Re: [PATCH 1/1] mm/slub.c: add a naive detection of double free or  corruption Alexander Popov <alex.popov@linux.com> - 2017-07-19 10:40 +0200
    Re: [PATCH 1/1] mm/slub.c: add a naive detection of double free or  corruption Christopher Lameter <cl@linux.com> - 2017-07-19 16:10 +0200

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