Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory: Important

Topic

Updated kernel-rt packages that fix several security issues and three bugs
are now available for Red Hat Enterprise MRG 2.3.

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

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

This update fixes the following security issues:

• A flaw was found in the way file permission checks for the
  "/dev/cpu/[x]/msr" files were performed in restricted root environments
  (for example, when using a capability-based security model). A local user
  with the ability to write to these files could use this flaw to escalate
  their privileges to kernel level, for example, by writing to the
  SYSENTER_EIP_MSR register. (CVE-2013-0268, Important)
  
• A race condition was found in the way the Linux kernel's ptrace
  implementation handled PTRACE_SETREGS requests when the debuggee was woken
  due to a SIGKILL signal instead of being stopped. A local, unprivileged
  user could use this flaw to escalate their privileges. (CVE-2013-0871,
  Important)
  
• An out-of-bounds access flaw was found in the way SOCK_DIAG_BY_FAMILY
  Netlink messages were processed in the Linux kernel. A local, unprivileged
  user could use this flaw to escalate their privileges. (CVE-2013-1763,
  Important)
  
• It was found that the default SCSI command filter does not accommodate
  commands that overlap across device classes. A privileged guest user could
  potentially use this flaw to write arbitrary data to a LUN that is
  passed-through as read-only. (CVE-2012-4542, Moderate)
  
• A flaw was found in the way the __skb_recv_datagram() function in the
  Linux kernel processed payload-less socket buffers (skb) when the MSG_PEEK
  option was requested. A local, unprivileged user could use this flaw to
  cause a denial of service (infinite loop). (CVE-2013-0290, Moderate)
  

The CVE-2012-4542 issue was discovered by Paolo Bonzini of Red Hat.

This update also fixes the following bugs:

• There was high contention on run-queue lock when load balancing before
  idling, causing latency spikes on high CPU core count systems. With this
  update, IPI is used to send notification to cores with pending work, and
  the cores push the work rather than trying to pull it, resolving this
  issue. (BZ#858396)
  
• Previously, ACPI lock was converted to an rt_mutex, leading to a
  traceback when scheduling while atomic. With this update, ACPI lock has
  been converted back to a raw spinlock. (BZ#909965)
  
• Fibre Channel (FC)/iSCSI device state was set to off-line and after a
  timeout, not set back to running. Such a device would not come back online
  after a fast_io_fail or timeout. With this update, an explicit check for
  the device being offline has been added, and the device is set back to
  running when re-initializing, allowing devices to recover after a failure
  or timeout. (BZ#912942)
  

Users should upgrade to these updated packages, which 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.

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

• MRG Realtime 2 x86_64

Fixes

• BZ - 858396 - latency issues on four-socket systems
• BZ - 875360 - CVE-2012-4542 kernel: block: default SCSI command filter does not accomodate commands overlap across device classes
• BZ - 908693 - CVE-2013-0268 kernel: x86/msr: /dev/cpu/*/msr local privilege escalation
• BZ - 911473 - CVE-2013-0290 kernel: net: infinite loop in __skb_recv_datagram()
• BZ - 911937 - CVE-2013-0871 kernel: race condition with PTRACE_SETREGS
• BZ - 915052 - CVE-2013-1763 kernel: sock_diag: out-of-bounds access to sock_diag_handlers[]

CVEs

• CVE-2013-0871
• CVE-2012-4542
• CVE-2013-0290
• CVE-2013-1763
• CVE-2013-0268

References

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

MRG Realtime 2

SRPM
kernel-rt-3.6.11-rt30.25.el6rt.src.rpm	SHA-256: c340f4f186c912a0095ec537dc07159de7d9d9e39565766fc527ee1c38f636ae
x86_64
kernel-rt-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: b67662ef478791560613fe988367ec7382c6a8caca257827699a473c8965fc4a
kernel-rt-debug-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: c8e127e009f9f16d304ecff612526e099b0605c87dad7e726e5bc117d256cf9c
kernel-rt-debug-debuginfo-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: 481d9d9da6ce09efa0e95b207101c9603579abc825ce582e5531ed74beae6cf9
kernel-rt-debug-devel-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: f773b1ffca3881d8c8ad1f0de28d97a57cd7ae06de735d633f4eed5801592cfe
kernel-rt-debuginfo-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: e56a5163a1c2f177b7a28b1321d9589d7e26dbe15624878ab7b586a04b61376c
kernel-rt-debuginfo-common-x86_64-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: bcf335c5e18df8c6f93e54beea5c9b1394637f9b43242e34db23d1121338928a
kernel-rt-devel-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: 7b12bb159693c36bd20694d282118522a791daff33be0e9b72c51661792ac46a
kernel-rt-doc-3.6.11-rt30.25.el6rt.noarch.rpm	SHA-256: 907cb1af86f83799da9ec144e8c01e7c91842ce5d6592f79928b18bfccb29d0b
kernel-rt-firmware-3.6.11-rt30.25.el6rt.noarch.rpm	SHA-256: d9c8acbeafccfa587e4f54bcbc887fdfda5d0405e5af19e353875c996760f860
kernel-rt-trace-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: 13d4b41f59b108df7f4c87cdeb65ccc21a5b48c8cd003725db820e88670d58d1
kernel-rt-trace-debuginfo-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: a61e86c2a700e8a16d928b8118c5fc23c1b5b74caa5615dec06de7dc02483101
kernel-rt-trace-devel-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: bfb0001f3e3b5ff013f140ac40d03f248075684c0a449b8606dc1a728f17bd1d
kernel-rt-vanilla-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: 36b008dbc7d96e8acb732c5d8752fa24943ecd56d909dae8498f7be75881624a
kernel-rt-vanilla-debuginfo-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: ea92a5f2d2f1b8c8d6e9de38874fbcc62187f836adf7f954a5623606ed10f9cf
kernel-rt-vanilla-devel-3.6.11-rt30.25.el6rt.x86_64.rpm	SHA-256: aa9fc2008ae8f5400a5cbd455ce8ceba1de3bf79fd8a9ddf86e00a27da2c64ff
mrg-rt-release-3.6.11-rt30.25.el6rt.noarch.rpm	SHA-256: 94bc98784c20bdcd3bca6e4a3a0bf38dc2145180fed9c41ca60f6b41f61b4a8d