7.2 - RHSA-2016:1657

Problem Description:

An update for kernel is now available for Red Hat Enterprise Linux 7.1 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 ComputeNode EUS (v. 7.1) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.1) - x86_64 Red Hat Enterprise Linux Server EUS (v. 7.1) - noarch, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Optional EUS (v. 7.1) - ppc64, ppc64le, s390x, x86_64

3. Description:

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

Security Fix(es):

* A flaw was found in the Linux kernel's keyring handling code, where in key_reject_and_link() an uninitialised variable would eventually lead to arbitrary free address which could allow attacker to use a use-after-free style attack. (CVE-2016-4470, Important)

* A flaw was found in the way certain interfaces of the Linux kernel's Infiniband subsystem used write() as bi-directional ioctl() replacement, which could lead to insufficient memory security checks when being invoked using the splice() system call. A local unprivileged user on a system with either Infiniband hardware present or RDMA Userspace Connection Manager Access module explicitly loaded, could use this flaw to escalate their privileges on the system. (CVE-2016-4565, Important)

* A flaw was found in the implementation of the Linux kernel's handling of networking challenge ack where an attacker is able to determine the shared counter which could be used to determine sequence numbers for TCP stream injection. (CVE-2016-5696, Important)

Red Hat would like to thank Jann Horn for reporting CVE-2016-4565 and Yue Cao (Cyber Security Group of the CS department of University of California in Riverside) for reporting CVE-2016-569