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Gentoo Linux Security Advisory                           GLSA 202409-22
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                                           https://security.gentoo.org/
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 Severity: Normal
    Title: GCC: Flawed Code Generation
     Date: September 24, 2024
     Bugs: #719466
       ID: 202409-22
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Synopsis
========
A vulnerability has been discovered in GCC, which can lead to flawed
code generation.
Background
==========
The GNU Compiler Collection includes front ends for C, C++, Objective-C,
Fortran, Ada, Go, D and Modula-2 as well as libraries for these
languages (libstdc++,...).
Affected packages
=================
Package        Vulnerable    Unaffected
-------------  ------------  ------------
sys-devel/gcc  < 10.0        >= 10.0
Description
===========
A vulnerability has been discovered in GCC. Please review the CVE
identifier referenced below for details.
Impact
======
The POWER9 backend in GNU Compiler Collection (GCC) could optimize
multiple calls of the __builtin_darn intrinsic into a single call, thus
reducing the entropy of the random number generator. This occurred
because a volatile operation was not specified. For example, within a
single execution of a program, the output of every __builtin_darn() call
may be the same.
Workaround
==========
There is no known workaround at this time.
Resolution
==========
All GCC users should upgrade to the latest version:
  # emerge --sync
  # emerge --ask --oneshot --verbose ">=sys-devel/gcc-10.0"
And then select it with gcc-config:
  # gcc-config latest
In this case, users should also rebuild all affected packages with
emerge -e, e.g.:
  # emerge --usepkg=n --emptytree @world
References
==========
[ 1 ] CVE-2019-15847
      https://nvd.nist.gov/vuln/detail/CVE-2019-15847
Availability
============
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:
 https://security.gentoo.org/glsa/202409-22
Concerns?
=========
Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
[email protected] or alternatively, you may file a bug at
https://bugs.gentoo.org.
License
=======
Copyright 2024 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).
The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.
https://creativecommons.org/licenses/by-sa/2.5