From: Zack Weinberg <zackw@panix.com>
To: Paul Eggert <eggert@cs.ucla.edu>, Florian Weimer <fweimer@redhat.com>
Cc: GNU C Library <libc-alpha@sourceware.org>,
Carlos O'Donell <carlos@redhat.com>,
"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Subject: Re: [PATCH 0/3] explicit_bzero v5
Date: Wed, 16 Nov 2016 14:56:00 -0000 [thread overview]
Message-ID: <545c2830-c00c-7eb9-65c0-cb8042a5069d@panix.com> (raw)
In-Reply-To: <b3064916-a082-9bb3-8715-9252d1fdecae@cs.ucla.edu>
On 11/15/2016 02:35 PM, Paul Eggert wrote:
> On 11/15/2016 10:54 AM, Zack Weinberg wrote:
>> If the adversary can read the stack at all, I suspect they've
>> already won, no matter what we do.
>
> That will likely be true in many applications, but not in all.
I doubt that very much. An adversary who can read the stack has access
to at least one pointer into the executable image (i.e. a return
address) and that is sufficient to walk the entire address space,
including all static data and the complete contents of the heap.
> It's worth documenting the issue for applications that put sensitive
> objects in the heap, as they might not expose these object addresses
> to the stack now
How on earth are they to operate on sensitive objects on the heap
without holding their addresses in function-local variables, which one
must assume do from time to time get spilled onto the stack?
zw
next prev parent reply other threads:[~2016-11-16 14:56 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-15 15:55 Zack Weinberg
2016-11-15 15:55 ` [PATCH 1/3] New string function explicit_bzero (from OpenBSD) Zack Weinberg
2016-11-15 15:55 ` [PATCH 2/3] Add fortification and inline optimization of explicit_bzero Zack Weinberg
2016-11-15 15:55 ` [PATCH 3/3] Use explicit_bzero where appropriate Zack Weinberg
2016-11-16 18:38 ` [PATCH 1/3] New string function explicit_bzero (from OpenBSD) Michael Kerrisk (man-pages)
2016-11-15 16:20 ` [PATCH 0/3] explicit_bzero v5 Paul Eggert
2016-11-15 17:46 ` Zack Weinberg
2016-11-15 18:02 ` Paul Eggert
2016-11-15 18:42 ` Florian Weimer
2016-11-15 18:54 ` Zack Weinberg
2016-11-15 19:35 ` Paul Eggert
2016-11-16 14:56 ` Zack Weinberg [this message]
2016-11-16 21:38 ` Paul Eggert
2016-11-16 18:34 ` Michael Kerrisk (man-pages)
2016-11-15 19:35 ` Paul Eggert
2016-11-16 14:58 ` Zack Weinberg
2016-11-15 21:12 ` Richard Henderson
2016-11-16 14:45 ` Zack Weinberg
2016-11-16 14:58 ` Andreas Schwab
2016-11-16 15:00 ` Zack Weinberg
2016-11-16 15:09 ` Andreas Schwab
2016-11-16 15:14 ` Zack Weinberg
2016-11-16 15:22 ` Andreas Schwab
2016-11-16 20:06 ` Richard Henderson
2016-11-16 2:03 ` Joseph Myers
2016-11-16 15:06 ` Zack Weinberg
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