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From: "scarybeasts at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug malloc/17344] New: Enhance glibc metadata hardening with the attached patch
Date: Wed, 03 Sep 2014 01:31:00 -0000	[thread overview]
Message-ID: <bug-17344-131@http.sourceware.org/bugzilla/> (raw)

https://sourceware.org/bugzilla/show_bug.cgi?id=17344

            Bug ID: 17344
           Summary: Enhance glibc metadata hardening with the attached
                    patch
           Product: glibc
           Version: 2.21
            Status: NEW
          Severity: normal
          Priority: P2
         Component: malloc
          Assignee: unassigned at sourceware dot org
          Reporter: scarybeasts at gmail dot com

Created attachment 7769
  --> https://sourceware.org/bugzilla/attachment.cgi?id=7769&action=edit
Check linked list integrity for the large sized chunk list too.

As a follow-on from my recent glibc exploit:

http://googleprojectzero.blogspot.com/2014/08/the-poisoned-nul-byte-2014-edition.html

I'd have really been slowed down, perhaps even stopped, if the the existing
metadata hardening tricks were extended to one more place. I've attached a
patch. It checks doubly-linked list integrity on unlink in one more place: the
linked list for larger-sized chunks.

Please consider applying it. There was already an assert() for this check, this
patch simply elevates this from an assert() to a runtime check.

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             reply	other threads:[~2014-09-03  1:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-03  1:31 scarybeasts at gmail dot com [this message]
2014-09-04 11:15 ` [Bug malloc/17344] " fweimer at redhat dot com
2014-09-10  8:23 ` fweimer at redhat dot com
2014-09-11  9:02 ` cvs-commit at gcc dot gnu.org
2014-09-11  9:03 ` fweimer at redhat dot com
2014-10-31 21:22 ` cvs-commit at gcc dot gnu.org

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