Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [day] [month] [year] [list]
Message-ID: <87r2x2uy3q.fsf@mid.deneb.enyo.de>
Date: Thu, 27 Jul 2017 09:40:09 +0200
From: Florian Weimer <fw@...eb.enyo.de>
To: oss-security@...ts.openwall.com
Subject: CVE-2017-11671: GCC generates incorrect code for RDRAND/RDSEED intrinsics

Earlier this year, a GCC bug was fixed which could lead to intrinsics
for RDRAND and (more likely) RDSEED to produce non-random results.
These instructions use the carry flag to report success or failure,
and GCC used to generate instruction sequences which clobbered the
flag before applications had a change to read it:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80180
  https://gcc.gnu.org/ml/gcc-patches/2017-03/msg01349.html

Practical impact is hopefully limited because the intrinsics are
difficult to use due to an unrelated GCC usability issue, and inline
assembly is not impacted by this issue.

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.