9.3 - RHSA-2015:1081

Problem Description:

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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - noarch, x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. 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.

4. 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

5. Bugs fixed (https://bugzilla.redhat.com/):

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