RHSA-2015:1081 - Security Advisory

Topic

Updated kernel packages that fix multiple security issues, several bugs,
and add various enhancements are now available for Red Hat Enterprise
Linux 6.

Red Hat Product Security has rated this update as having Important security
impact. Common Vulnerability Scoring System (CVSS) base scores, which give
detailed severity ratings, are available for each vulnerability from the
CVE links in the References section.

Description

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

• It was found that the Linux kernel's implementation of vectored pipe read

and write functionality did not take into account the I/O vectors that were
already processed when retrying after a failed atomic access operation,
potentially resulting in memory corruption due to an I/O vector array
overrun. A local, unprivileged user could use this flaw to crash the system
or, potentially, escalate their privileges on the system. (CVE-2015-1805,
Important)

• A buffer overflow flaw was found in the way the Linux kernel's Intel

AES-NI instructions optimized version of the RFC4106 GCM mode decryption
functionality handled fragmented packets. A remote attacker could use this
flaw to crash, or potentially escalate their privileges on, a system over a
connection with an active AES-GCM mode IPSec security association.
(CVE-2015-3331, Important)

• An information leak flaw was found in the way the Linux kernel changed

certain segment registers and thread-local storage (TLS) during a context
switch. A local, unprivileged user could use this flaw to leak the user
space TLS base address of an arbitrary process. (CVE-2014-9419, Low)

• It was found that the Linux kernel's ISO file system implementation did

not correctly limit the traversal of Rock Ridge extension Continuation
Entries (CE). An attacker with physical access to the system could use this
flaw to trigger an infinite loop in the kernel, resulting in a denial of
service. (CVE-2014-9420, Low)

• An information leak flaw was found in the way the Linux kernel's Virtual

Dynamic Shared Object (vDSO) implementation performed address
randomization. A local, unprivileged user could use this flaw to leak
kernel memory addresses to user-space. (CVE-2014-9585, Low)

Red Hat would like to thank Carl Henrik Lunde for reporting
CVE-2014-9420. The security impact of the CVE-2015-1805 issue was
discovered by Red Hat.

This update also fixes several bugs and adds various enhancements.
Documentation for these changes is available from the Technical Notes
document linked to in the References section.

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues and add these
enhancements. The system must be rebooted for this update to take effect.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 i386
• Red Hat Enterprise Linux Server - AUS 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Server - TUS 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 i386
• Red Hat Enterprise Linux EUS Compute Node 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 1175235 - CVE-2014-9420 Kernel: fs: isofs: infinite loop in CE record entries
• BZ - 1177260 - CVE-2014-9419 kernel: partial ASLR bypass through TLS base addresses leak
• BZ - 1181054 - CVE-2014-9585 kernel: ASLR bruteforce possible for vdso library
• BZ - 1202855 - CVE-2015-1805 kernel: pipe: iovec overrun leading to memory corruption
• BZ - 1213322 - CVE-2015-3331 Kernel: crypto: buffer overruns in RFC4106 implementation using AESNI

CVEs

• CVE-2015-3331
• CVE-2015-1805
• CVE-2014-9419
• CVE-2014-9585
• CVE-2014-9420

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.6_Technical_Notes/kernel.html