Description of problem fixed ----------------------------- There are 2 problems fixed with this efix: 1. A heap-based buffer overflow exists in the GNU C library, commonly known as glibc. The affected library component is the ss_hostname_digits_dots() function used by both gethostbyname() and gethostbyname2() glibc functions. Programs calling these functions may be vulnerable to a buffer overflow, exploitable by local, as well as remote users, to execute arbitrary code on affected systems. 2. The dynamic linker in the 4.7.2 toolchain was incorrectly set to point to the dynamic linker of the 4.4.7 toolchain. This forced users to specify the correct dynamic linker on compiles. Steps to take before installing the RPMs for this fix ----------------------------------------------------- By default installing this efix will delete the existing toolchain. To avoid this make sure /bgsys/linux/.leaveBGQToolchain exists. In this way if you want to go back to using the original toolchain just reset the gnu-linux sym link back to the original toolchain. cd /bgsys/drivers/ppcfloor ln -s /bgsys/drivers/toolchain/V1R2M2_base/gnu-linux gnu-linux Installing the rpms in this efix will kick off a toolchain build. This takes about 2 hours, the rpm install is not hung. Steps to take after installing the RPMs for this fix ---------------------------------------------------- Relink applications with the newly build toolchain. IO nodes need to be rebooted To build the 4.7.2 toolchain cd /bgsys/drivers/ppcfloor/toolchain-4.7.2 Run this command fully qualified /bgsys/drivers/ppcfloor/toolchain-4.7.2/buildToolChain.sh Getting the list of installed fixes ----------------------------------- To find out which efixes are currently installed and not superceded, run the following command: rpm -qf `/bin/ls -d /bgsys/drivers/V?R?M? | tail -1` /opt/teal/ibm --queryformat "%{release}\n" | sort -nu __________________________________________________________________________________________________________ Security bulletin for efix014: glibc GHOST vulnerability. Title Security Bulletin: GNU C library (glibc) vulnerability affects Blue Gene/Q toolchain (CVE-2015-0235) Summary GNU C library (glibc) vulnerability that has been referred to as GHOST affects Blue Gene/Q Toolchain. Vulnerability Details CVEID: CVE-2015-0235 DESCRIPTION:The gethostbyname functions of the GNU C Library (glibc) are vulnerable to a buffer overflow. By sending a specially crafted, but valid hostname argument, a remote attacker could overflow a buffer and execute arbitrary code on the system with the privileges of the targeted process or cause the process to crash. The impact of an attack depends on the implementation details of the targeted application or operating system. This issue is being referred to as the "Ghost" vulnerability. CVSS Base Score: 7.6 CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/100386for the current score CVSS Environmental Score*: Undefined CVSS Vector: (AV:N/AC:H/Au:N/C:C/I:C/A:C) Affected Products and Versions Blue Gene/Q V1R2M2 Toolchain v4.4.7 Blue Gene/Q V1R2M2 Toolchain v4.7.2 Versions of Blue Gene/Q Toolchain that are no longer supported Remediation/Fixes Users of the Blue Gene/Q Toolchain v4.4.7 must upgrade to bgq-V1R2M2-toolchain-1.2.2-14.ppc64.rpm. Users of the Blue Gene/Q Toolchain v4.7.2 must upgrade to bgq-V1R2M2-toolchain-4.7.2-1.2.2-14.ppc64.rpm. Users of versions of Blue Gene/Q Toolchain no longer supported must upgrade to one of the two supported versions. Users that use the gethostbyname functions in their applications must rebuild them using the new toolchain. IBM recommends that you review your entire environment to identify vulnerable releases of glibc including your Operating Systems and take appropriate mitigation and remediation actions. Please contact your Operating System provider for more information. From: Thomas Gooding/Rochester/IBM To: Mike Nelson/Rochester/IBM@IBMUS, Tom Budnik/Rochester/IBM@IBMUS Cc: Serban Maerean/Austin/IBM@IBMUS Date: 02/10/2015 12:43 PM Subject: efix014 security bulletin Hi Mike, Tom, Here is the security bulletin for efix014: glibc GHOST vulnerability. Can you include with the efix and publish? Thanks! Tom Title Security Bulletin: GNU C library (glibc) vulnerability affects Blue Gene/Q toolchain (CVE-2015-0235) Summary GNU C library (glibc) vulnerability that has been referred to as GHOST affects Blue Gene/Q Toolchain. Vulnerability Details CVEID: CVE-2015-0235 DESCRIPTION:The gethostbyname functions of the GNU C Library (glibc) are vulnerable to a buffer overflow. By sending a specially crafted, but valid hostname argument, a remote attacker could overflow a buffer and execute arbitrary code on the system with the privileges of the targeted process or cause the process to crash. The impact of an attack depends on the implementation details of the targeted application or operating system. This issue is being referred to as the "Ghost" vulnerability. CVSS Base Score: 7.6 CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/100386for the current score CVSS Environmental Score*: Undefined CVSS Vector: (AV:N/AC:H/Au:N/C:C/I:C/A:C) Affected Products and Versions Blue Gene/Q V1R2M2 Toolchain v4.4.7 Blue Gene/Q V1R2M2 Toolchain v4.7.2 Versions of Blue Gene/Q Toolchain that are no longer supported Remediation/Fixes Users of the Blue Gene/Q Toolchain v4.4.7 must upgrade to bgq-V1R2M2-toolchain-1.2.2-14.ppc64.rpm. Users of the Blue Gene/Q Toolchain v4.7.2 must upgrade to bgq-V1R2M2-toolchain-4.7.2-1.2.2-14.ppc64.rpm. Users of versions of Blue Gene/Q Toolchain no longer supported must upgrade to one of the two supported versions. Users that use the gethostbyname functions in their applications must rebuild them using the new toolchain. IBM recommends that you review your entire environment to identify vulnerable releases of glibc including your Operating Systems and take appropriate mitigation and remediation actions. Please contact your Operating System provider for more information. Workarounds and Mitigations None known Reference Complete CVSS Guide On-line Calculator V2 Related Information IBM Secure Engineering Web Portal IBM Product Security Incident Response Blog Acknowledgement None Change History 11 February 2015: Original Version Published *The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin. Disclaimer According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES "AS IS" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.