7.8 - RHSA-2016:1100

Problem Description:

An update for kernel is now available for Red Hat Enterprise Linux 6.6 Extended Update Support.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux HPC Node EUS (v. 6.6) - noarch, x86_64 Red Hat Enterprise Linux HPC Node Optional EUS (v. 6.6) - x86_64 Red Hat Enterprise Linux Server EUS (v. 6.6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional EUS (v. 6.6) - i386, ppc64, s390x, x86_64

3. Description:

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

Security Fix(es):

* Two flaws were found in the way the Linux kernel's networking implementation handled UDP packets with incorrect checksum values. A remote attacker could potentially use these flaws to trigger an infinite loop in the kernel, resulting in a denial of service on the system, or cause a denial of service in applications using the edge triggered epoll functionality. (CVE-2015-5364, CVE-2015-5366, Important)

Bug Fix(es):

* In anon_vma data structure, the degree counts number of child anon_vmas and of VMAs that point to this anon_vma. In the unlink_anon_vma() function, when its list is empty, anon_vma is going to be freed whether the external refcount is zero or not, so the parent's degree should be decremented. However, failure to decrement the degree triggered a BUG_ON() signal in unlink_anon_vma(). The provided patch fixes this bug, and the degree is now decremented as expected. (BZ#1326027)

Enhancement(s):

* The ixgbe NIC driver has been upgraded to upstream version 4.2.1, which provides a number of bug fixes and enhancements over the previous version. Notably:

NULL pointer crashes related to VLAN support have been fixed

Two more devices from the Intel X550 Ethernet controller family are now supported: IDs 15AC and 15AD

Several PHY-related problems have been addressed: link disruptions and link flapping

Added PHY-related support for Intel X550

System performance has been improved

(BZ#1315702)

4. Solution:

For details on how to apply this update, which includes the changes described in this advisory, refer to:

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

The system must be rebooted for this update to take effect.

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

1239029 - CVE-2015-5366 CVE-2015-5364 kernel: net: incorrect processing of checksums in UDP implementation