RHSA-2015:0726 - Security Advisory

Topic

Updated kernel packages that fix two security issues and several bugs are
now available for Red Hat Enterprise Linux 7.

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 Infiniband subsystem did not

properly sanitize input parameters while registering memory regions from
user space via the (u)verbs API. A local user with access to a
/dev/infiniband/uverbsX device could use this flaw to crash the system or,
potentially, escalate their privileges on the system. (CVE-2014-8159,
Important)

• A use-after-free flaw was found in the way the Linux kernel's SCTP

implementation handled authentication key reference counting during INIT
collisions. A remote attacker could use this flaw to crash the system or,
potentially, escalate their privileges on the system. (CVE-2015-1421,
Important)

Red Hat would like to thank Mellanox for reporting the CVE-2014-8159 issue.
The CVE-2015-1421 issue was discovered by Sun Baoliang of Red Hat.

This update also fixes the following bugs:

• In certain systems with multiple CPUs, when a crash was triggered on one

CPU with an interrupt handler and this CPU sent Non-Maskable Interrupt
(NMI) to another CPU, and, at the same time, ioapic_lock had already been
acquired, a deadlock occurred in ioapic_lock. As a consequence, the kdump
service could become unresponsive. This bug has been fixed and kdump now
works as expected. (BZ#1197742)

• On Lenovo X1 Carbon 3rd Gen, X250, and T550 laptops, the thinkpad_acpi

module was not properly loaded, and thus the function keys and radio
switches did not work. This update applies a new string pattern of BIOS
version, which fixes this bug, and function keys and radio switches now
work as intended. (BZ#1197743)

• During a heavy file system load involving many worker threads, all worker

threads in the pool became blocked on a resource, and no manager thread
existed to create more workers. As a consequence, the running processes
became unresponsive. With this update, the logic around manager creation
has been changed to assure that the last worker thread becomes a manager
thread and does not start executing work items. Now, a manager thread
exists, spawns new workers as needed, and processes no longer hang.
(BZ#1197744)

• If a thin-pool's metadata enters read-only or fail mode, for example, due

to thin-pool running out of metadata or data space, any attempt to make
metadata changes such as creating a thin device or snapshot thin device
should error out cleanly. However, previously, the kernel code returned
verbose and alarming error messages to the user. With this update, due to
early trapping of attempt to make metadata changes, informative errors are
displayed, no longer unnecessarily alarming the user. (BZ#1197745)

• When running Red Hat Enterprise Linux as a guest on Microsoft Hyper-V

hypervisor, the storvsc module did not return the correct error code for
the upper level Small Computer System Interface (SCSI) subsystem. As a
consequence, a SCSI command failed and storvsc did not handle such a
failure properly under some conditions, for example, when RAID devices were
created on top of storvsc devices. An upstream patch has been applied to
fix this bug, and storvsc now returns the correct error code in the
described situation. (BZ#1197749)

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. 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 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.1 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.2 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.1 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.2 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.1 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.2 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.1 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.2 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.1 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.3 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.2 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1181166 - CVE-2014-8159 kernel: infiniband: uverbs: unprotected physical memory access
• BZ - 1196581 - CVE-2015-1421 kernel: net: slab corruption from use after free on INIT collisions

CVEs

• CVE-2014-8159
• CVE-2015-1421

References

• https://access.redhat.com/security/updates/classification/#important