Red Hat Update for kernel-rt (RHSA-2016:1883)

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

The kernel-rt packages have been upgraded to version 3.10.0-327.rt56.197, which provides a number of bug fixes over the previous version. (BZ#1366059)

Security Fix(es):

* A security flaw was found in the Linux kernel in the mark_source_chains() function in "net/ipv4/netfilter/ip_tables.c". It is possible for a user-supplied "ipt_entry" structure to have a large "next_offset" field. This field is not bounds checked prior to writing to a counter value at the supplied offset. (CVE-2016-3134, Important)

* A flaw was discovered in processing setsockopt for 32 bit processes on 64 bit systems. This flaw will allow attackers to alter arbitrary kernel memory when unloading a kernel module. This action is usually restricted to root-privileged users but can also be leveraged if the kernel is compiled with CONFIG_USER_NS and CONFIG_NET_NS and the user is granted elevated privileges. (CVE-2016-4997, Important)

* An out-of-bounds heap memory access leading to a Denial of Service, heap disclosure, or further impact was found in setsockopt(). The function call is normally restricted to root, however some processes with cap_sys_admin may also be able to trigger this flaw in privileged container environments. (CVE-2016-4998, Moderate)

This action is usually restricted to root-privileged users but can also be leveraged if the kernel is compiled with CONFIG_USER_NS and CONFIG_NET_NS and the user is granted elevated privileges. (CVE-2016-4997, Important)
The function call is normally restricted to root, however some processes with cap_sys_admin may also be able to trigger this flaw in privileged container environments. (CVE-2016-4998, Moderate)

Upgrade to the latest packages which contain a patch. Refer to Applying Package Updates to RHEL system for details.

Refer to Red Hat security advisory RHSA-2016:1883 to address this issue and obtain more information.

Patch:
Following are links for downloading patches to fix the vulnerabilities:

RHSA-2016:1883: Red Hat Enterprise Linux