Synopsis

Important: kernel security and bug fix update

Type/Severity

Security Advisory: Important

Topic

Updated kernel packages that fix multiple security issues and several bugs
are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team 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

Security:

• An integer overflow flaw, leading to a heap-based buffer overflow, was

found in the way the Intel i915 driver in the Linux kernel handled the
allocation of the buffer used for relocation copies. A local user with
console access could use this flaw to cause a denial of service or escalate
their privileges. (CVE-2013-0913, Important)

• A buffer overflow flaw was found in the way UTF-8 characters were

converted to UTF-16 in the utf8s_to_utf16s() function of the Linux kernel's
FAT file system implementation. A local user able to mount a FAT file
system with the "utf8=1" option could use this flaw to crash the system or,
potentially, to escalate their privileges. (CVE-2013-1773, Important)

• A flaw was found in the way KVM handled guest time updates when the

buffer the guest registered by writing to the MSR_KVM_SYSTEM_TIME machine
state register (MSR) crossed a page boundary. A privileged guest user could
use this flaw to crash the host or, potentially, escalate their privileges,
allowing them to execute arbitrary code at the host kernel level.
(CVE-2013-1796, Important)

• A potential use-after-free flaw was found in the way KVM handled guest

time updates when the GPA (guest physical address) the guest registered by
writing to the MSR_KVM_SYSTEM_TIME machine state register (MSR) fell into a
movable or removable memory region of the hosting user-space process (by
default, QEMU-KVM) on the host. If that memory region is deregistered from
KVM using KVM_SET_USER_MEMORY_REGION and the allocated virtual memory
reused, a privileged guest user could potentially use this flaw to
escalate their privileges on the host. (CVE-2013-1797, Important)

• A flaw was found in the way KVM emulated IOAPIC (I/O Advanced

Programmable Interrupt Controller). A missing validation check in the
ioapic_read_indirect() function could allow a privileged guest user to
crash the host, or read a substantial portion of host kernel memory.
(CVE-2013-1798, Important)

• A race condition in install_user_keyrings(), leading to a NULL pointer

dereference, was found in the key management facility. A local,
unprivileged user could use this flaw to cause a denial of service.
(CVE-2013-1792, Moderate)

• A NULL pointer dereference in the XFRM implementation could allow a local

user who has the CAP_NET_ADMIN capability to cause a denial of service.
(CVE-2013-1826, Moderate)

• A NULL pointer dereference in the Datagram Congestion Control Protocol

(DCCP) implementation could allow a local user to cause a denial of
service. (CVE-2013-1827, Moderate)

• Information leak flaws in the XFRM implementation could allow a local

user who has the CAP_NET_ADMIN capability to leak kernel stack memory to
user-space. (CVE-2012-6537, Low)

• Two information leak flaws in the Asynchronous Transfer Mode (ATM)

subsystem could allow a local, unprivileged user to leak kernel stack
memory to user-space. (CVE-2012-6546, Low)

• An information leak was found in the TUN/TAP device driver in the

networking implementation. A local user with access to a TUN/TAP virtual
interface could use this flaw to leak kernel stack memory to user-space.
(CVE-2012-6547, Low)

• An information leak in the Bluetooth implementation could allow a local

user who has the CAP_NET_ADMIN capability to leak kernel stack memory to
user-space. (CVE-2013-0349, Low)

• A use-after-free flaw was found in the tmpfs implementation. A local user

able to mount and unmount a tmpfs file system could use this flaw to cause
a denial of service or, potentially, escalate their privileges.
(CVE-2013-1767, Low)

• A NULL pointer dereference was found in the Linux kernel's USB Inside Out

Edgeport Serial Driver implementation. An attacker with physical access to
a system could use this flaw to cause a denial of service. (CVE-2013-1774,
Low)

Red Hat would like to thank Andrew Honig of Google for reporting
CVE-2013-1796, CVE-2013-1797, and CVE-2013-1798. CVE-2013-1792 was
discovered by Mateusz Guzik of Red Hat EMEA GSS SEG Team.

Solution

This update also fixes several bugs. Documentation for these changes will
be available shortly from the Technical Notes document linked to in the
References section.

Users should 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.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not
use "rpm -Uvh" as that will remove the running kernel binaries from
your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

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 6.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.4 i386
• Red Hat Enterprise Linux Server - AUS 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• 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 6.4 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.4 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 Update Support from RHUI 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 i386
• Red Hat Gluster Storage Server for On-premise 2.1 x86_64
• Red Hat Storage for Public Cloud (via RHUI) 2.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 914298 - CVE-2013-0349 kernel: bluetooth HIDP implementation information disclosure
• BZ - 915592 - CVE-2013-1767 Kernel: tmpfs: fix use-after-free of mempolicy object
• BZ - 916115 - CVE-2013-1773 kernel: VFAT slab-based buffer overflow
• BZ - 916191 - CVE-2013-1774 Kernel: USB io_ti driver NULL pointer dereference in routine chase_port
• BZ - 916646 - CVE-2013-1792 Kernel: keys: race condition in install_user_keyrings()
• BZ - 917012 - CVE-2013-1796 kernel: kvm: buffer overflow in handling of MSR_KVM_SYSTEM_TIME
• BZ - 917013 - CVE-2013-1797 kernel: kvm: after free issue with the handling of MSR_KVM_SYSTEM_TIME
• BZ - 917017 - CVE-2013-1798 kernel: kvm: out-of-bounds access in ioapic indirect register reads
• BZ - 919164 - CVE-2013-1827 Kernel: dccp: check ccid before NULL poiter dereference
• BZ - 919384 - CVE-2013-1826 Kernel: xfrm_user: return error pointer instead of NULL
• BZ - 920471 - CVE-2013-0913 Kernel: drm/i915: heap writing overflow
• BZ - 922344 - CVE-2012-6547 Kernel: net/tun: ioctl() based information leaks
• BZ - 922383 - CVE-2012-6546 Kernel: atm: information leak in getsockopt & getsockname
• BZ - 922424 - CVE-2012-6537 Kernel: xfrm_user information leaks copy_to_user_

CVEs

• CVE-2013-1773
• CVE-2013-1798
• CVE-2013-1796
• CVE-2013-1797
• CVE-2012-6547
• CVE-2012-6546
• CVE-2013-1826
• CVE-2012-6537
• CVE-2013-1792
• CVE-2013-1827
• CVE-2013-1767
• CVE-2013-0913
• CVE-2013-0349
• CVE-2013-1774
• CVE-2012-6538

References