RHSA-2015:0674 - Security Advisory

Topic

Updated kernel packages that fix multiple security issues and several bugs
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.

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 flaw was found in the way the Linux kernel's splice() system call

validated its parameters. On certain file systems, a local, unprivileged
user could use this flaw to write past the maximum file size, and thus
crash the system. (CVE-2014-7822, Moderate)

• A flaw was found in the way the Linux kernel's netfilter subsystem

handled generic protocol tracking. As demonstrated in the Stream Control
Transmission Protocol (SCTP) case, a remote attacker could use this flaw to
bypass intended iptables rule restrictions when the associated connection
tracking module was not loaded on the system. (CVE-2014-8160, Moderate)

• It was found that the fix for CVE-2014-3601 was incomplete: the Linux

kernel's kvm_iommu_map_pages() function still handled IOMMU mapping
failures incorrectly. A privileged user in a guest with an assigned host
device could use this flaw to crash the host. (CVE-2014-8369, Moderate)

Red Hat would like to thank Mellanox for reporting CVE-2014-8159, and Akira
Fujita of NEC for reporting CVE-2014-7822.

Bug fixes:

• The maximum amount of entries in the IPv6 route table

(net.ipv6.route.max_size) was 4096, and every route towards this maximum
size limit was counted. Communication to more systems was impossible when
the limit was exceeded. Now, only cached routes are counted, which
guarantees that the kernel does not run out of memory, but the user can now
install as many routes as the memory allows until the kernel indicates it
can no longer handle the amount of memory and returns an error message.

In addition, the default "net.ipv6.route.max_size" value has been increased
to 16384 for performance improvement reasons. (BZ#1177581)

• When the user attempted to scan for an FCOE-served Logical Unit Number

(LUN), after an initial LUN scan, a kernel panic occurred in
bnx2fc_init_task. System scanning for LUNs is now stable after LUNs have
been added. (BZ#1179098)

• Under certain conditions, such as when attempting to scan the network for

LUNs, a race condition in the bnx2fc driver could trigger a kernel panic in
bnx2fc_init_task. A patch fixing a locking issue that caused the race
condition has been applied, and scanning the network for LUNs no longer
leads to a kernel panic. (BZ#1179098)

• Previously, it was not possible to boot the kernel on Xen hypervisor in

PVHVM mode if more than 32 vCPUs were specified in the guest configuration.
Support for more than 32 vCPUs has been added, and the kernel now boots
successfully in the described situation. (BZ#1179343)

• When the NVMe driver allocated a namespace queue, it indicated that it

was a request-based driver when it was actually a block I/O-based driver.
Consequently, when NVMe driver was loaded along with a request-based dm
device, the system could terminate unexpectedly or become unresponsive when
attempting to access data. The NVMe driver no longer sets the
QUEUE_FLAG_STACKABLE bit when allocating a namespace queue and
device-mapper no longer perceives NVMe driver as request-based; system
hangs or crashes no longer occur. (BZ#1180555)

• If a user attempted to apply an NVRAM firmware update when running the

tg3 module provided with Red Hat Enterprise Linux 6.6 kernels, the update
could fail. As a consequence, the Network Interface Card (NIC) could stay
in an unusable state and this could prevent the entire system from booting.
The tg3 module has been updated to correctly apply firmware updates.
(BZ#1182903)

• Support for key sizes of 256 and 192 bits has been added to AES-NI.

(BZ#1184332)

Solution

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.

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 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 i386
• Red Hat Enterprise Linux Server - AUS 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Server - TUS 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 i386
• Red Hat Enterprise Linux EUS Compute Node 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 1156518 - CVE-2014-8369 kernel: kvm: excessive pages un-pinning in kvm_iommu_map error path
• BZ - 1163792 - CVE-2014-7822 kernel: splice: lack of generic write checks
• BZ - 1181166 - CVE-2014-8159 kernel: infiniband: uverbs: unprotected physical memory access
• BZ - 1182059 - CVE-2014-8160 kernel: iptables restriction bypass if a protocol handler kernel module not loaded

CVEs

• CVE-2014-7822
• CVE-2014-8160
• CVE-2014-8369
• CVE-2014-8159

References

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